With the development of Service-Oriented Architecture, more and more researches have provided automatic and semi-automatic approaches to end-user. Users can construct their own applications with web services. However, it is hard for most end-users to customize the interfaces of applications with current service composition methods. To address this issue, an interface generation model was proposed to provide customized user interface and interaction workflow. In this model, knowledge was involved to instruct the workflow of interaction. Templates were adopted to describe the user interface. Some significant points, such as user definition, data profile, user interaction workflow, interface description, were discussed in detail. A prototype system was implemented. Some demos have been shown to verify the customized interface generation model. With this model, end-users can define the interfaces and interaction workflows of web services with rules and templates. It supplies the gap of user interface in service composition. Compared with the current interface generation in service composition, the proposed model is more flexible and more effective for end-users.