diff --git a/README.md b/README.md
index 759bd41..0214e4c 100644
--- a/README.md
+++ b/README.md
@@ -37,9 +37,9 @@ ios:
 
 log:
   format: "string" # string or json
-  access_log: "stdout"
+  access_log: "stdout" # stdout: output to console, or define log path like "log/access_log"
   access_level: "debug"
-  error_log: "stderr"
+  error_log: "stderr" # stderr: output to console, or define log path like "log/error_log"
   error_level: "error"
 ```
 
diff --git a/gorush/notification.go b/gorush/notification.go
index 2861c6e..e84d5e6 100644
--- a/gorush/notification.go
+++ b/gorush/notification.go
@@ -50,6 +50,7 @@ type RequestPushNotification struct {
 	ContentAvailable bool     `json:"content_available,omitempty"`
 
 	// Android
+	ApiKey                string           `json:"api_key,omitempty"`
 	To                    string           `json:"to,omitempty"`
 	CollapseKey           string           `json:"collapse_key,omitempty"`
 	DelayWhileIdle        bool             `json:"delay_while_idle,omitempty"`
@@ -311,10 +312,15 @@ func GetAndroidNotification(req RequestPushNotification) gcm.HttpMessage {
 }
 
 func PushToAndroid(req RequestPushNotification) bool {
+	var apiKey string
 
 	notification := GetAndroidNotification(req)
 
-	res, err := gcm.SendHttp(PushConf.Android.ApiKey, notification)
+	if apiKey = PushConf.Android.ApiKey; req.ApiKey != "" {
+		apiKey = req.ApiKey
+	}
+
+	res, err := gcm.SendHttp(apiKey, notification)
 
 	if err != nil {
 		// GCM server error
diff --git a/gorush/notification_test.go b/gorush/notification_test.go
index 0445798..c4c45b0 100644
--- a/gorush/notification_test.go
+++ b/gorush/notification_test.go
@@ -261,7 +261,27 @@ func TestPushToAndroidWrongToken(t *testing.T) {
 	assert.True(t, success)
 }
 
-func TestPushToAndroidRightToken(t *testing.T) {
+func TestPushToAndroidRightTokenForJSONLog(t *testing.T) {
+	PushConf = BuildDefaultPushConf()
+
+	PushConf.Android.Enabled = true
+	PushConf.Android.ApiKey = os.Getenv("ANDROID_API_KEY")
+	// log for json
+	PushConf.Log.Format = "json"
+
+	android_token := os.Getenv("ANDROID_TEST_TOKEN")
+
+	req := RequestPushNotification{
+		Tokens:   []string{android_token, "bbbbb"},
+		Platform: 2,
+		Message:  "Welcome",
+	}
+
+	success := PushToAndroid(req)
+	assert.True(t, success)
+}
+
+func TestPushToAndroidRightTokenForStringLog(t *testing.T) {
 	PushConf = BuildDefaultPushConf()
 
 	PushConf.Android.Enabled = true
@@ -278,3 +298,23 @@ func TestPushToAndroidRightToken(t *testing.T) {
 	success := PushToAndroid(req)
 	assert.True(t, success)
 }
+
+func TestOverwriteAndroidApiKey(t *testing.T) {
+	PushConf = BuildDefaultPushConf()
+
+	PushConf.Android.Enabled = true
+	PushConf.Android.ApiKey = os.Getenv("ANDROID_API_KEY")
+
+	android_token := os.Getenv("ANDROID_TEST_TOKEN")
+
+	req := RequestPushNotification{
+		Tokens:   []string{android_token, "bbbbb"},
+		Platform: 2,
+		Message:  "Welcome",
+		// overwrite android api key
+		ApiKey: "1234",
+	}
+
+	success := PushToAndroid(req)
+	assert.False(t, success)
+}
diff --git a/gorush/server_test.go b/gorush/server_test.go
index f6fd780..b108dda 100644
--- a/gorush/server_test.go
+++ b/gorush/server_test.go
@@ -205,8 +205,6 @@ func TestHalfSuccessAndroidPushHandler(t *testing.T) {
 
 	PushConf.Android.Enabled = true
 	PushConf.Android.ApiKey = os.Getenv("ANDROID_API_KEY")
-	// log for json
-	PushConf.Log.Format = "json"
 
 	android_token := os.Getenv("ANDROID_TEST_TOKEN")
 
@@ -229,8 +227,6 @@ func TestAllSuccessAndroidPushHandler(t *testing.T) {
 
 	PushConf.Android.Enabled = true
 	PushConf.Android.ApiKey = os.Getenv("ANDROID_API_KEY")
-	// log for json
-	PushConf.Log.Format = "json"
 
 	android_token := os.Getenv("ANDROID_TEST_TOKEN")
 
@@ -246,7 +242,4 @@ func TestAllSuccessAndroidPushHandler(t *testing.T) {
 
 			assert.Equal(t, http.StatusOK, r.Code)
 		})
-
-	// wait push response
-	time.Sleep(3000 * time.Millisecond)
 }