To promote the model-based software engineering development of user interfaces, this paper proposes an EIP model that can design user interfaces in abstract and can support automatic generation of user interfaces. In the model, functionality and composition are taken as the direct descriptive objects of engineering modeling, making user interface construction more intuitive and easily acceptable; and a layered approach is adopted for both abstraction and presentation of user interface description, making the modeling powerful enough in dealing with complex user interfaces. In the research, internal data models and their related user interface design patterns are isolated as the user interface modeling components, making presentation and layout more easily constructed. Based on EIP and tools, the automatic generation of user interfaces is achieved.