Towards the development of the new urban design system, this paper shows the development of an interactive design support system. Starting with an introduction of several cases in other fields, the paper discusses the significance and the specificity of the design method using the tool and clarifies its potential. Furthermore, it evaluates the use of the program developed in this study, depending on impressions of users and specifies the direction of further development. As the result, it is proved that the program is opened to communicate with designer's intention and also is able to continue developing by the communication itself.