Pen-Based user interface software is widely applicable due to its natural and efficient interaction style, whose important characteristics are interaction-centered and individual by user-required. In order to map the intention of users into the designs exactly and efficiently, PUIDM(Pen based User Interfaces software Domain Model) is presented, which is described and analyzed from the aspects of context, component, UI features and architecture, and implemented based on XML. Moreover, a user-centered design process based on the PUIDM is introduced. Experiments show that PUIDM can guide the process of design exactly and efficiently and make the designed software achieve the demand of usability.