The objective of this study was to test whether the Kinect motion-sensing interactive system (KMIS) enhanced students' English vocabulary learning, while also comparing the system's effectiveness against a traditional computer-mouse interface. Both interfaces utilized an interactive game with a questioning strategy. One-hundred and twenty participants were chosen from an elementary school. The students were divided into three groups: Kinect, computer-mouse, and control. The participants' vocabularies were evaluated three times during a pre-test, a post-test, and a 1-month post-test. The following results were obtained: (1) there was a partially disordinal interaction relationship between the three groups and the three tests. Post-hoc comparison showed that the three tests have an order relationship. (2) The within group comparisons, both for the motion-sensing and computer-mouse groups which utilized an interactive game with a questioning strategy, displayed a relatively significant long-term retention. (3) In the between group comparison, the two interactive groups (computer-mouse and motion-sensing group) did not reach significant difference in English vocabulary learning. This means the motion-sensing interface of the KMIS was not a key-factor to affecting short-term or long-term learning retention. Therefore, our suggestion is that teachers can adopt interactive games with a questioning strategy to enhance students' long-term English vocabulary retention.