Motor tasks involve employing muscles (effectors) to execute movements. Effector independence, which states the role of the effectors in a programmed action is independent of specific muscles, is an important hypothesis in motor control theory and application such as physical therapy and athletic training. However, evidences for the hypothesis often are mixed. The main purpose of the present study was to determine whether effector independence occurred in motor programming level and/or parameter level. In the experiment, participants (n=24) were asked to grip a hand dynamometer to practice three targets of force production in a MP 100 data acquisition station. Feedback about performance was provided in acquisition session. Transfer test, which shifted hand grip from left to right, was conducted about 24 hrs after the acquisition. The results showed that participants improved the accuracy of their force productions with practice. More importantly, transfer test didn’t degrade relative force performance compared to the performance in acquisition although absolute force error tended to be higher. It indicated that the relative feature of force production was relatively consistent after shifting effectors. Effector independence should occur in motor programming level.Keyword(s): performance, research