diff --git a/ios/sdk/WeexSDK/Sources/Bridge/WXBridgeContext.m b/ios/sdk/WeexSDK/Sources/Bridge/WXBridgeContext.m
index 89287e5be0..195b7c8ab5 100644
--- a/ios/sdk/WeexSDK/Sources/Bridge/WXBridgeContext.m
+++ b/ios/sdk/WeexSDK/Sources/Bridge/WXBridgeContext.m
@@ -567,6 +567,7 @@ - (void)createInstance:(NSString *)instanceIdString
                         JSObjectSetPrototype(instanceContextRef, JSValueToObject(instanceContextRef, [instanceContextEnvironment valueForProperty:key].JSValueRef, NULL), JSObjectGetPrototype(instanceContextRef, instanceGlobalObject));
                     }
                     JSObjectSetProperty(instanceContextRef, instanceGlobalObject, propertyName, [instanceContextEnvironment valueForProperty:key].JSValueRef, 0, NULL);
+                    JSStringRelease(propertyName);
                 }
                 
                 if (WX_SYS_VERSION_LESS_THAN(@"10.2")) {