This paper presents the designing process of Tourist Guiding app on iPhone. This app aims for assisting tourists to schedule their trip plan in detail. The designing process consisted of three phases: research, interface design, user evaluation. In order to focus on user-centered  research, two methods were carried out questionnaire survey, interview with participants. After the research was done, the results of research were analyzed and summarized so that the potential requirements were collected. Those requirements would decide the inclusive features of this app, such as navigation,plan a trip,search for transportation.  Meanwhile, the interfaces of this app were designed on the platform: Photoshop. Lastly, the paper prototype's evaluation was conducted with four participants. The valuable feedbacks was given and the improvements of the interfaces were done.