The paper describes the interaction design for mobile input method. In order to further the interaction design, we proposed the usability testing to testify the design details in the two new input method interactive prototypes (T9 style keyboard and QT style keyboard). Quantitative data (accuracy rate of keystroke) was collected which was used to measure the effectiveness of different styles of buttons and related UI designs in the demos. And the users’ subjective attitudes and user experiences on the different design were collected through interactive demo. Finally the user research and usability testing results improve the validity of meaning-centered design approach for input method.