The development of Web applications should be supported by business professionals themselves since Web applications must be modified frequently based on their needs. In our recent studies with the three-tier architecture of user interface, business logic and database, the construction of the graphical user interface and the simple database system is supported by using application framework and visual modeling technologies. As for the business logic, however, it is rather difficult to support it by the same way because there are various kinds of business logic. This paper describes the classification of the business logic of Web applications with case studies. These results indicate that the classification of business logic is dependent on how the business logic is expressed. Then, for end-user-initiative development, the business logic should be expressed from the view of the service providers or the support systems instead of the view of the clients. Finally it is confirmed that the template based on the UI-driven approach is useful for requirement specifications of business logic.