diff --git a/account.go b/account.go
index 82625fc..fbd19e5 100644
--- a/account.go
+++ b/account.go
@@ -1,7 +1,7 @@
 package kumex
 
 import (
-	"encoding/json"
+	"github.com/json-iterator/go"
 	"net/http"
 )
 
@@ -65,12 +65,12 @@ func (as *ApiService) SubApiKeys(apiKey, subName string) (*ApiResponse, error) {
 type SubApiKeysModel []*SubApiKeyModel
 
 type SubApiKeyModel struct {
-	SubName     string      `json:"subName"`
-	Remark      string      `json:"remark"`
-	ApiKey      string      `json:"apiKey"`
-	Permission  string      `json:"permission"`
-	IpWhitelist string      `json:"ipWhitelist"`
-	CreatedAt   json.Number `json:"createdAt"`
+	SubName     string          `json:"subName"`
+	Remark      string          `json:"remark"`
+	ApiKey      string          `json:"apiKey"`
+	Permission  string          `json:"permission"`
+	IpWhitelist string          `json:"ipWhitelist"`
+	CreatedAt   jsoniter.Number `json:"createdAt"`
 }
 
 // CreateSubApiKey This endpoint can be used to create Futures APIs for sub-accounts.
@@ -80,14 +80,14 @@ func (as *ApiService) CreateSubApiKey(p map[string]string) (*ApiResponse, error)
 }
 
 type CreateSubApiKeyRes struct {
-	SubName     string      `json:"subName"`
-	Remark      string      `json:"remark"`
-	ApiKey      string      `json:"apiKey"`
-	Permission  string      `json:"permission"`
-	IpWhitelist string      `json:"ipWhitelist"`
-	CreatedAt   json.Number `json:"createdAt"`
-	ApiSecret   string      `json:"apiSecret"`
-	Passphrase  string      `json:"passphrase"`
+	SubName     string          `json:"subName"`
+	Remark      string          `json:"remark"`
+	ApiKey      string          `json:"apiKey"`
+	Permission  string          `json:"permission"`
+	IpWhitelist string          `json:"ipWhitelist"`
+	CreatedAt   jsoniter.Number `json:"createdAt"`
+	ApiSecret   string          `json:"apiSecret"`
+	Passphrase  string          `json:"passphrase"`
 }
 
 // ModifySubApiKey TThis endpoint can be used to modify sub-account Futures APIs.
@@ -130,24 +130,24 @@ func (as *ApiService) SubAccountsBalance(currency string) (*ApiResponse, error)
 
 type SubAccountBalanceModel struct {
 	Summary struct {
-		AccountEquityTotal    json.Number `json:"accountEquityTotal"`
-		UnrealisedPNLTotal    json.Number `json:"unrealisedPNLTotal"`
-		MarginBalanceTotal    json.Number `json:"marginBalanceTotal"`
-		PositionMarginTotal   json.Number `json:"positionMarginTotal"`
-		OrderMarginTotal      json.Number `json:"orderMarginTotal"`
-		FrozenFundsTotal      json.Number `json:"frozenFundsTotal"`
-		AvailableBalanceTotal json.Number `json:"availableBalanceTotal"`
-		Currency              string      `json:"currency"`
+		AccountEquityTotal    jsoniter.Number `json:"accountEquityTotal"`
+		UnrealisedPNLTotal    jsoniter.Number `json:"unrealisedPNLTotal"`
+		MarginBalanceTotal    jsoniter.Number `json:"marginBalanceTotal"`
+		PositionMarginTotal   jsoniter.Number `json:"positionMarginTotal"`
+		OrderMarginTotal      jsoniter.Number `json:"orderMarginTotal"`
+		FrozenFundsTotal      jsoniter.Number `json:"frozenFundsTotal"`
+		AvailableBalanceTotal jsoniter.Number `json:"availableBalanceTotal"`
+		Currency              string          `json:"currency"`
 	} `json:"summary"`
 	Accounts []struct {
-		AccountName      string      `json:"accountName"`
-		AccountEquity    json.Number `json:"accountEquity"`
-		UnrealisedPNL    json.Number `json:"unrealisedPNL"`
-		MarginBalance    json.Number `json:"marginBalance"`
-		PositionMargin   json.Number `json:"positionMargin"`
-		OrderMargin      json.Number `json:"orderMargin"`
-		FrozenFunds      json.Number `json:"frozenFunds"`
-		AvailableBalance json.Number `json:"availableBalance"`
-		Currency         string      `json:"currency"`
+		AccountName      string          `json:"accountName"`
+		AccountEquity    jsoniter.Number `json:"accountEquity"`
+		UnrealisedPNL    jsoniter.Number `json:"unrealisedPNL"`
+		MarginBalance    jsoniter.Number `json:"marginBalance"`
+		PositionMargin   jsoniter.Number `json:"positionMargin"`
+		OrderMargin      jsoniter.Number `json:"orderMargin"`
+		FrozenFunds      jsoniter.Number `json:"frozenFunds"`
+		AvailableBalance jsoniter.Number `json:"availableBalance"`
+		Currency         string          `json:"currency"`
 	} `json:"accounts"`
 }
diff --git a/account_test.go b/account_test.go
index 47e116d..ce3e34f 100644
--- a/account_test.go
+++ b/account_test.go
@@ -5,11 +5,10 @@ import (
 )
 
 func TestApiService_AccountOverview(t *testing.T) {
-	t.SkipNow()
 
 	s := NewApiServiceFromEnv()
 	p := map[string]string{}
-	p["currency"] = "XBT"
+	p["currency"] = "USDT"
 
 	rsp, err := s.AccountOverview(p)
 	if err != nil {
diff --git a/funding.go b/funding.go
index ba52683..b0ed28a 100644
--- a/funding.go
+++ b/funding.go
@@ -46,3 +46,18 @@ func (as *ApiService) FundingRatesTimeRange(symbol, from, to string) (*ApiRespon
 	})
 	return as.Call(req)
 }
+
+type TradeFeesV1Resp struct {
+	Symbol       string `json:"symbol"`
+	TakerFeeRate string `json:"takerFeeRate"`
+	MakerFeeRate string `json:"makerFeeRate"`
+}
+
+// TradeFeesV1  This interface is for the actual fee rate of the trading pair.
+// The fee rate of your sub-account is the same as that of the master account.
+func (as *ApiService) TradeFeesV1(symbol string) (*ApiResponse, error) {
+	req := NewRequest(http.MethodGet, "/api/v1/trade-fees", map[string]string{
+		"symbol": symbol,
+	})
+	return as.Call(req)
+}
diff --git a/funding_test.go b/funding_test.go
index 4bb93eb..3c09e03 100644
--- a/funding_test.go
+++ b/funding_test.go
@@ -47,3 +47,17 @@ func TestApiService_FundingRatesTimeRange(t *testing.T) {
 		t.Log(ToJsonString(o))
 	}
 }
+
+func TestApiService_TradeFeesV1(t *testing.T) {
+	s := NewApiServiceFromEnv()
+	rsp, err := s.TradeFeesV1("XBTUSDTM")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	os := TradeFeesV1Resp{}
+	if err := rsp.ReadData(&os); err != nil {
+		t.Fatal(err)
+	}
+	t.Log(ToJsonString(os))
+}
diff --git a/go.mod b/go.mod
index ad40cc6..3b54dfb 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,7 @@
 module github.com/Kucoin/kucoin-futures-go-sdk
 
 require (
+	github.com/google/go-querystring v1.1.0 // indirect
 	github.com/gorilla/websocket v1.4.0
 	github.com/json-iterator/go v1.1.12
 	github.com/pkg/errors v0.8.1
diff --git a/go.sum b/go.sum
index 6a4faf9..bfd5c24 100644
--- a/go.sum
+++ b/go.sum
@@ -1,6 +1,9 @@
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/google/go-cmp v0.5.2/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/go-querystring v1.1.0 h1:AnCroh3fv4ZBgVIf1Iwtovgjaw/GiKJo8M8yD/fhyJ8=
+github.com/google/go-querystring v1.1.0/go.mod h1:Kcdr2DB4koayq7X8pmAG4sNG59So17icRSOU623lUBU=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
 github.com/gorilla/websocket v1.4.0 h1:WDFjx/TMzVgy9VdMMQi2K2Emtwi2QcUQsztZ/zLaH/Q=
 github.com/gorilla/websocket v1.4.0/go.mod h1:E7qHFY5m1UJ88s3WnNqhKjPHQ0heANvMoAMk2YaljkQ=
@@ -25,3 +28,4 @@ github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33 h1:I6FyU15t786LL7oL/hn43zqTuEGr4PN7F4XJ1p4E3Y8=
 golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
diff --git a/helper.go b/helper.go
index db4f181..df9008e 100644
--- a/helper.go
+++ b/helper.go
@@ -1,7 +1,7 @@
 package kumex
 
 import (
-	"encoding/json"
+	"github.com/json-iterator/go"
 	"strconv"
 )
 
@@ -12,7 +12,7 @@ func IntToString(i int64) string {
 
 // ToJsonString converts any value to JSON string.
 func ToJsonString(v interface{}) string {
-	b, err := json.Marshal(v)
+	b, err := jsoniter.Marshal(v)
 	if err != nil {
 		return ""
 	}
diff --git a/http.go b/http.go
index 91696c7..9855e3d 100644
--- a/http.go
+++ b/http.go
@@ -32,7 +32,7 @@ type Request struct {
 }
 
 // NewRequest creates a instance of Request.
-func NewRequest(method, path string, params map[string]string) *Request {
+func NewRequest(method, path string, params interface{}) *Request {
 	r := &Request{
 		Method:  method,
 		Path:    path,
@@ -51,17 +51,21 @@ func NewRequest(method, path string, params map[string]string) *Request {
 	return r
 }
 
-func (r *Request) addParams(params map[string]string) {
+func (r *Request) addParams(p interface{}) {
+	if p == nil {
+		return
+	}
 	switch r.Method {
 	case http.MethodGet, http.MethodDelete:
-		for key, value := range params {
+		if v, ok := p.(url.Values); ok {
+			r.Query = v
+			return
+		}
+		for key, value := range p.(map[string]string) {
 			r.Query.Add(key, value)
 		}
 	default:
-		if params == nil {
-			return
-		}
-		b, err := jsoniter.Marshal(params)
+		b, err := jsoniter.Marshal(p)
 		if err != nil {
 			log.Panic("Cannot marshal params to JSON string:", err.Error())
 		}
diff --git a/market.go b/market.go
index a289066..297809a 100644
--- a/market.go
+++ b/market.go
@@ -1,7 +1,7 @@
 package kumex
 
 import (
-	"encoding/json"
+	"github.com/json-iterator/go"
 	"net/http"
 )
 
@@ -230,7 +230,7 @@ func (as *ApiService) FundingRate(Symbol string) (*ApiResponse, error) {
 }
 
 type TradeStatisticsModel struct {
-	TurnoverOf24h json.Number `json:"turnoverOf24h"`
+	TurnoverOf24h jsoniter.Number `json:"turnoverOf24h"`
 }
 
 // TradeStatistics Get 24h trade statistics.
diff --git a/order.go b/order.go
index 205c5e1..7e73126 100644
--- a/order.go
+++ b/order.go
@@ -13,6 +13,12 @@ func (as *ApiService) CreateOrder(params map[string]string) (*ApiResponse, error
 	return as.Call(req)
 }
 
+// CreateOrderTest places a new order.
+func (as *ApiService) CreateOrderTest(params map[string]string) (*ApiResponse, error) {
+	req := NewRequest(http.MethodPost, "/api/v1/orders/test", params)
+	return as.Call(req)
+}
+
 // A CancelOrderResultModel represents the result of CancelOrder().
 type CancelOrderResultModel struct {
 	CancelledOrderIds []string `json:"cancelledOrderIds"`
@@ -76,7 +82,7 @@ type OrderModel struct {
 	PostOnly       bool   `json:"postOnly"`
 	Hidden         bool   `json:"hidden"`
 	IceBerg        bool   `json:"iceberg"`
-	VisibleSize    string `json:"visibleSize"`
+	VisibleSize    int64  `json:"visibleSize"`
 	Leverage       string `json:"leverage"`
 	ForceHold      bool   `json:"forceHold"`
 	CloseOrder     bool   `json:"closeOrder"`
@@ -134,3 +140,44 @@ func (as *ApiService) CancelOrderClientId(clientOid, symbol string) (*ApiRespons
 	req := NewRequest(http.MethodDelete, "/api/v1/orders/client-order/"+clientOid, p)
 	return as.Call(req)
 }
+
+type CreateOrderReq struct {
+	// BASE PARAMETERS
+	ClientOid     string `json:"clientOid"`
+	Side          string `json:"side"`
+	Symbol        string `json:"symbol,omitempty"`
+	Leverage      string `json:"leverage,omitempty"`
+	Type          string `json:"type,omitempty"`
+	Remark        string `json:"remark,omitempty"`
+	Stop          string `json:"stop,omitempty"`
+	StopPrice     string `json:"stopPrice,omitempty"`
+	StopPriceType string `json:"stopPriceType,omitempty"`
+	ReduceOnly    string `json:"reduceOnly,omitempty"`
+	CloseOrder    string `json:"closeOrder,omitempty"`
+	ForceHold     string `json:"forceHold,omitempty"`
+	Stp           string `json:"stp,omitempty"`
+
+	// MARKET ORDER PARAMETERS
+	Size string `json:"size,omitempty"`
+
+	// LIMIT ORDER PARAMETERS
+	Price       string `json:"price,omitempty"`
+	TimeInForce string `json:"timeInForce,omitempty"`
+	PostOnly    bool   `json:"postOnly,omitempty"`
+	Hidden      bool   `json:"hidden,omitempty"`
+	IceBerg     bool   `json:"iceberg,omitempty"`
+	VisibleSize string `json:"visibleSize,omitempty"`
+}
+
+type CreateOrderRes struct {
+	OrderId   string `json:"orderId"`
+	ClientOid string `json:"clientOid"`
+	Symbol    string `json:"symbol"`
+}
+type CreateMultiOrdersRes []*CreateOrderRes
+
+// CreateMultiOrders places multi order.
+func (as *ApiService) CreateMultiOrders(p []*CreateOrderReq) (*ApiResponse, error) {
+	req := NewRequest(http.MethodPost, "/api/v1/orders/multi", p)
+	return as.Call(req)
+}
diff --git a/order_test.go b/order_test.go
index 1c3d473..418a491 100644
--- a/order_test.go
+++ b/order_test.go
@@ -258,3 +258,38 @@ func TestApiService_CancelOrderClientId(t *testing.T) {
 	}
 	t.Log(ToJsonString(o))
 }
+
+func TestApiService_CreateMultiOrders(t *testing.T) {
+
+	s := NewApiServiceFromEnv()
+	p := make([]*CreateOrderReq, 0)
+	p = append(p, &CreateOrderReq{
+		ClientOid: IntToString(time.Now().UnixNano()),
+		Side:      "buy",
+		Symbol:    "XBTUSDTM",
+		Leverage:  "1",
+		Type:      "limit",
+		Size:      "1",
+		Price:     "0.3",
+	})
+
+	p = append(p, &CreateOrderReq{
+		ClientOid: IntToString(time.Now().UnixNano()),
+		Side:      "buy",
+		Symbol:    "XBTUSDTM",
+		Leverage:  "1",
+		Type:      "limit",
+		Size:      "1",
+		Price:     "0.2",
+	})
+
+	rsp, err := s.CreateMultiOrders(p)
+	if err != nil {
+		t.Fatal(err)
+	}
+	o := &CreateMultiOrdersRes{}
+	if err := rsp.ReadData(o); err != nil {
+		t.Fatal(err)
+	}
+	t.Log(ToJsonString(o))
+}
diff --git a/pagination.go b/pagination.go
index 87a821d..b32faf3 100644
--- a/pagination.go
+++ b/pagination.go
@@ -1,6 +1,8 @@
 package kumex
 
-import "encoding/json"
+import (
+	"github.com/json-iterator/go"
+)
 
 // A PaginationParam represents the pagination parameters `currentPage` `pageSize` in a request .
 type PaginationParam struct {
@@ -15,14 +17,14 @@ func (p *PaginationParam) ReadParam(params map[string]string) {
 
 // A PaginationModel represents the pagination in a response.
 type PaginationModel struct {
-	CurrentPage int64           `json:"currentPage"`
-	PageSize    int64           `json:"pageSize"`
-	TotalNum    int64           `json:"totalNum"`
-	TotalPage   int64           `json:"totalPage"`
-	RawItems    json.RawMessage `json:"items"` // delay parsing
+	CurrentPage int64               `json:"currentPage"`
+	PageSize    int64               `json:"pageSize"`
+	TotalNum    int64               `json:"totalNum"`
+	TotalPage   int64               `json:"totalPage"`
+	RawItems    jsoniter.RawMessage `json:"items"` // delay parsing
 }
 
 // ReadItems read the `items` into v.
 func (p *PaginationModel) ReadItems(v interface{}) error {
-	return json.Unmarshal(p.RawItems, v)
+	return jsoniter.Unmarshal(p.RawItems, v)
 }
diff --git a/position.go b/position.go
index 01bf751..86dbf19 100644
--- a/position.go
+++ b/position.go
@@ -1,6 +1,7 @@
 package kumex
 
 import (
+	"github.com/google/go-querystring/query"
 	"net/http"
 )
 
@@ -79,3 +80,69 @@ func (as *ApiService) DepositMargin(params map[string]string) (*ApiResponse, err
 	req := NewRequest(http.MethodPost, "/api/v1/position/margin/deposit-margin", params)
 	return as.Call(req)
 }
+
+// MaxWithdrawMarginV1 This interface can query the maximum amount of margin that the current position supports withdrawal.
+func (as *ApiService) MaxWithdrawMarginV1(symbol string) (*ApiResponse, error) {
+	req := NewRequest(http.MethodGet, "/api/v1/margin/maxWithdrawMargin", map[string]string{"symbol": symbol})
+	return as.Call(req)
+}
+
+type WithdrawMarginV1Req struct {
+	Symbol         string `json:"symbol"`
+	WithdrawAmount string `json:"withdrawAmount"`
+}
+
+// WithdrawMarginV1 Remove Margin Manually
+func (as *ApiService) WithdrawMarginV1(r *WithdrawMarginV1Req) (*ApiResponse, error) {
+	req := NewRequest(http.MethodPost, "/api/v1/margin/withdrawMargin", r)
+	return as.Call(req)
+}
+
+type GetPositionsHistoryV1Req struct {
+	Symbol string `url:"symbol,omitempty"`
+	From   int64  `url:"from,omitempty"`
+	To     int64  `url:"to,omitempty"`
+	Limit  int    `url:"limit,omitempty"`
+	PageID int    `url:"pageId,omitempty"`
+}
+
+type PositionsHistoryItem struct {
+	CloseID           string   `json:"closeId"`
+	PositionID        string   `json:"positionId"`
+	UID               int64    `json:"uid"`
+	UserID            string   `json:"userId"`
+	Symbol            string   `json:"symbol"`
+	SettleCurrency    string   `json:"settleCurrency"`
+	Leverage          string   `json:"leverage"`
+	Type              string   `json:"type"`
+	Side              *string  `json:"side"`
+	CloseSize         *float64 `json:"closeSize"`
+	PNL               string   `json:"pnl"`
+	RealisedGrossCost string   `json:"realisedGrossCost"`
+	WithdrawPNL       string   `json:"withdrawPnl"`
+	ROE               *float64 `json:"roe"`
+	TradeFee          string   `json:"tradeFee"`
+	FundingFee        string   `json:"fundingFee"`
+	OpenTime          int64    `json:"openTime"`
+	CloseTime         int64    `json:"closeTime"`
+	OpenPrice         *float64 `json:"openPrice"`
+	ClosePrice        *float64 `json:"closePrice"`
+}
+
+type GetPositionsHistoryV1Resp struct {
+	CurrentPage int                    `json:"currentPage"`
+	PageSize    int                    `json:"pageSize"`
+	TotalNum    int                    `json:"totalNum"`
+	TotalPage   int                    `json:"totalPage"`
+	Items       []PositionsHistoryItem `json:"items"`
+}
+
+// GetPositionsHistoryV1 This interface can query position history information records
+func (as *ApiService) GetPositionsHistoryV1(r *GetPositionsHistoryV1Req) (*ApiResponse, error) {
+	v, err := query.Values(r)
+	if err != nil {
+		return nil, err
+	}
+	req := NewRequest(http.MethodGet, "/api/v1/history-positions", v)
+	return as.Call(req)
+}
diff --git a/position_test.go b/position_test.go
index 7748487..483edaa 100644
--- a/position_test.go
+++ b/position_test.go
@@ -106,3 +106,52 @@ func TestApiService_DepositMargin(t *testing.T) {
 		t.Error("Empty key 'id'")
 	}
 }
+
+func TestApiService_MaxWithdrawMarginV1(t *testing.T) {
+	s := NewApiServiceFromEnv()
+
+	rsp, err := s.MaxWithdrawMarginV1("XBTUSDTM")
+	if err != nil {
+		t.Fatal(err)
+	}
+	var data string
+	if err := rsp.ReadData(&data); err != nil {
+		t.Fatal(err)
+	}
+	t.Log(data)
+}
+
+func TestApiService_WithdrawMarginV1(t *testing.T) {
+
+	s := NewApiServiceFromEnv()
+
+	r := &WithdrawMarginV1Req{
+		Symbol:         "XBTUSDTM",
+		WithdrawAmount: "0.1",
+	}
+	rsp, err := s.WithdrawMarginV1(r)
+	if err != nil {
+		t.Fatal(err)
+	}
+	var data string
+	if err := rsp.ReadData(&data); err != nil {
+		t.Fatal(err)
+	}
+	t.Log(data)
+}
+func TestApiService_GetPositionsHistoryV1(t *testing.T) {
+	s := NewApiServiceFromEnv()
+
+	r := &GetPositionsHistoryV1Req{
+		Symbol: "PEPEUSDTM",
+	}
+	rsp, err := s.GetPositionsHistoryV1(r)
+	if err != nil {
+		t.Fatal(err)
+	}
+	data := GetPositionsHistoryV1Resp{}
+	if err := rsp.ReadData(&data); err != nil {
+		t.Fatal(err)
+	}
+	t.Log(ToJsonString(data))
+}
diff --git a/transfer.go b/transfer.go
index cab1e58..8e87ca1 100644
--- a/transfer.go
+++ b/transfer.go
@@ -1,7 +1,7 @@
 package kumex
 
 import (
-	"encoding/json"
+	"github.com/json-iterator/go"
 	"math/big"
 	"net/http"
 )
@@ -88,23 +88,23 @@ func (as *ApiService) TransferOutV3(currency, recAccountType, amount string) (*A
 }
 
 type TransferOutV3Res struct {
-	ApplyId        string      `json:"applyId"`
-	BizNo          string      `json:"bizNo"`
-	PayAccountType string      `json:"payAccountType"`
-	PayTag         string      `json:"payTag"`
-	Remark         string      `json:"remark"`
-	RecAccountType string      `json:"recAccountType"`
-	RecTag         string      `json:"recTag"`
-	RecRemark      string      `json:"recRemark"`
-	RecSystem      string      `json:"recSystem"`
-	Status         string      `json:"status"`
-	Currency       string      `json:"currency"`
-	Amount         string      `json:"amount"`
-	Fee            string      `json:"fee"`
-	Sn             big.Int     `json:"sn"`
-	Reason         string      `json:"reason"`
-	CreatedAt      json.Number `json:"createdAt"`
-	UpdatedAt      json.Number `json:"updatedAt"`
+	ApplyId        string          `json:"applyId"`
+	BizNo          string          `json:"bizNo"`
+	PayAccountType string          `json:"payAccountType"`
+	PayTag         string          `json:"payTag"`
+	Remark         string          `json:"remark"`
+	RecAccountType string          `json:"recAccountType"`
+	RecTag         string          `json:"recTag"`
+	RecRemark      string          `json:"recRemark"`
+	RecSystem      string          `json:"recSystem"`
+	Status         string          `json:"status"`
+	Currency       string          `json:"currency"`
+	Amount         string          `json:"amount"`
+	Fee            string          `json:"fee"`
+	Sn             big.Int         `json:"sn"`
+	Reason         string          `json:"reason"`
+	CreatedAt      jsoniter.Number `json:"createdAt"`
+	UpdatedAt      jsoniter.Number `json:"updatedAt"`
 }
 
 // TransferIn The amount to be transferred will be deducted from the KuCoin Futures Account.
diff --git a/websocket.go b/websocket.go
index 1ee480a..01848da 100644
--- a/websocket.go
+++ b/websocket.go
@@ -2,7 +2,6 @@ package kumex
 
 import (
 	"crypto/tls"
-	"encoding/json"
 	"fmt"
 	"math/rand"
 	"net/http"
@@ -11,6 +10,7 @@ import (
 	"time"
 
 	"github.com/gorilla/websocket"
+	"github.com/json-iterator/go"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 )
@@ -123,15 +123,15 @@ func NewUnsubscribeMessage(topic string, privateChannel bool) *WebSocketUnsubscr
 // A WebSocketDownstreamMessage represents a message from the WebSocket server to client.
 type WebSocketDownstreamMessage struct {
 	*WebSocketMessage
-	Sn      string          `json:"sn"`
-	Topic   string          `json:"topic"`
-	Subject string          `json:"subject"`
-	RawData json.RawMessage `json:"data"`
+	Sn      string              `json:"sn"`
+	Topic   string              `json:"topic"`
+	Subject string              `json:"subject"`
+	RawData jsoniter.RawMessage `json:"data"`
 }
 
 // ReadData read the data in channel.
 func (m *WebSocketDownstreamMessage) ReadData(v interface{}) error {
-	return json.Unmarshal(m.RawData, v)
+	return jsoniter.Unmarshal(m.RawData, v)
 }
 
 // A WebSocketClient represents a connection to WebSocket server.