diff --git a/sdk/sdk_interface.go b/sdk/sdk_interface.go
index 9e1c0a6f844f254fc75ac63cb88715ba9a1a57dc..e05bc456a43c8a6c7972f418cbdcd5ff9857be39 100644
--- a/sdk/sdk_interface.go
+++ b/sdk/sdk_interface.go
@@ -207,7 +207,10 @@ type SDKInterface interface {
 	// Deprecated
 	GetSenderAddr() (string, error)
 	// Sender Get the address of the sender address, if the contract is called by another contract, the result will be
-	// the caller contract's address
+	// the caller contract's address.
+	// Sender will return system contract address when executing the init or upgrade method (If you need to return the
+	// user address, we recommend using Origin method here), because the init and upgrade methods are cross-contract
+	// txs (system contract -> common contract).
 	// @return1: sender address
 	// @return2: 获取错误信息
 	Sender() (string, error)