diff --git a/bce/config.go b/bce/config.go
index 243b4c81..cd632ec2 100644
--- a/bce/config.go
+++ b/bce/config.go
@@ -26,7 +26,7 @@ import (
 
 // Constants and default values for the package bce
 const (
-	SDK_VERSION                          = "0.9.202"
+	SDK_VERSION                          = "0.9.203"
 	URI_PREFIX                           = "/" // now support uri without prefix "v1" so just set root path
 	DEFAULT_DOMAIN                       = "baidubce.com"
 	DEFAULT_PROTOCOL                     = "http"
diff --git a/doc/RDS.md b/doc/RDS.md
index 14b00491..b8039dfa 100644
--- a/doc/RDS.md
+++ b/doc/RDS.md
@@ -315,7 +315,7 @@ for _, e := range result.InstanceIds {
 ```go
 // import "github.com/baidubce/bce-sdk-go/services/rds"
 
-args := &rds.CreateReadReplicaArgs{
+args := &rds.CreateRDSReadReplicaArgs{
     //主实例ID，必选
     SourceInstanceId: "sourceInstanceId"
     // 计费相关参数，PaymentTiming取值为 预付费：Prepaid，后付费：Postpaid；Reservation：支付方式为后付费时不需要设置，预付费时必须设置；必选
@@ -363,8 +363,8 @@ for _, e := range result.InstanceIds {
 > 注意: 
 > - 需要在云数据库 RDS 主实例的基础上进行创建
 > - 实例可选套餐详见(https://cloud.baidu.com/doc/RDS/s/9jwvz0wd3)
-> - 仅数据库类型为 MySQL 的主实例支持创建只读实例
-> - 只读实例的数据库引擎和数据库版本与主实例相同，无需设置，主实例版本最低是 MySQL 5.6
+> - 仅数据库类型为 MySQL、PostgreSql 的主实例支持创建只读实例
+> - 只读实例的数据库引擎和数据库版本与主实例相同，无需设置，主实例版本最低是 MySQL 5.6、PostgreSql 10
 > - 只读实例的磁盘容量不能小于主实例的磁盘容量
 > - 只读实例的 vpcId 需跟主实例一致
 > - 一个云数据库 RDS 实例，最多只能有 5 个只读实例
diff --git a/services/rds/client_test.go b/services/rds/client_test.go
index 11d635ec..66fb309f 100644
--- a/services/rds/client_test.go
+++ b/services/rds/client_test.go
@@ -215,7 +215,14 @@ func TestClient_UpdateAccountPrivileges(t *testing.T) {
 	ExpectEqual(t.Errorf, nil, err)
 }
 func TestClient_CreateReadReplica(t *testing.T) {
-	args := &CreateReadReplicaArgs{
+	subnets := SubnetMap{
+		ZoneName: "cn-bj-d",
+		SubnetId: "sbn-dqafncqsy3y4",
+	}
+	var sub = []SubnetMap{
+		subnets,
+	}
+	args := &CreateRDSReadReplicaArgs{
 		SourceInstanceId: RDS_ID,
 		CpuCount:         1,
 		MemoryCapacity:   2,
@@ -224,6 +231,7 @@ func TestClient_CreateReadReplica(t *testing.T) {
 			PaymentTiming: "Postpaid",
 		},
 		ClientToken: getClientToken(),
+		Subnets:     sub,
 	}
 	time.Sleep(30 * time.Second)
 	isAvailable(RDS_ID)
diff --git a/services/rds/model.go b/services/rds/model.go
index 92d641db..93318083 100644
--- a/services/rds/model.go
+++ b/services/rds/model.go
@@ -110,6 +110,27 @@ type CreateReadReplicaArgs struct {
 	ResourceGroupId  string           `json:"resourceGroupId,omitempty"`
 }
 
+type CreateRDSReadReplicaArgs struct {
+	ClientToken           string           `json:"-"`
+	Billing               Billing          `json:"billing"`
+	PurchaseCount         int              `json:"purchaseCount,omitempty"`
+	SourceInstanceId      string           `json:"sourceInstanceId"`
+	InstanceName          string           `json:"instanceName,omitempty"`
+	CpuCount              int              `json:"cpuCount"`
+	MemoryCapacity        float64          `json:"memoryCapacity"`
+	VolumeCapacity        int              `json:"volumeCapacity"`
+	ZoneNames             []string         `json:"zoneNames,omitempty"`
+	VpcId                 string           `json:"vpcId,omitempty"`
+	IsDirectPay           bool             `json:"isDirectPay,omitempty"`
+	Subnets               []SubnetMap      `json:"subnets,omitempty"`
+	Tags                  []model.TagModel `json:"tags,omitempty"`
+	DiskIoType            string           `json:"diskIoType,omitempty"`
+	Ovip                  string           `json:"ovip,omitempty"`
+	EntryPort             string           `json:"entryPort,omitempty"`
+	ResourceGroupId       string           `json:"resourceGroupId,omitempty"`
+	IsInheritMasterAuthip bool             `json:"isInheritMasterAuthip,omitempty"`
+}
+
 type CreateRdsProxyArgs struct {
 	ClientToken      string           `json:"-"`
 	Billing          Billing          `json:"billing"`
diff --git a/services/rds/rds.go b/services/rds/rds.go
index ebb40c96..3e715c80 100644
--- a/services/rds/rds.go
+++ b/services/rds/rds.go
@@ -74,7 +74,7 @@ func (c *Client) CreateRds(args *CreateRdsArgs) (*CreateResult, error) {
 // RETURNS:
 //   - *InstanceIds: the result of create a readReplica RDS, contains the readReplica RDS's instanceIds
 //   - error: nil if success otherwise the specific error
-func (c *Client) CreateReadReplica(args *CreateReadReplicaArgs) (*CreateResult, error) {
+func (c *Client) CreateReadReplica(args *CreateRDSReadReplicaArgs) (*CreateResult, error) {
 	if args == nil {
 		return nil, fmt.Errorf("unset args")
 	}