We present a role accessibility definition based Web application generation. A role accessibility definition specifies what kind of data access can be done by which type of roles of users. From a given role accessibility definition, we can automatically derive data model, business logic and user interface to generate simple Web applications. With additional definitions of page transition and general computation using existing Web service functions, then we can generate more general type of Web applications. We can use fine grained Web service functions for handling tables or external Web service functions on the Web. Our approach will help us (esp. non-programmers) create a variety of Web applications such as questionnaire systems, student assignment evaluation systems, and so on.