User-centered design plays a significant part in product design. GOMS user behavior model analyze the interface from the aspects of both users and objects, which helps the designers to create a user-friendly interface in an efficient way. In this paper, GOMS model was used to predict the efficiency of the two versions of input interface on a touch-screen mobile phone. In addition, the experiment was conducted to collect the data under the real scenarios, and paired-sample T test was employed to analyze the data. The results indicate the GOMS prediction model can be used to evaluate the efficiency of the mobile phone interface.