Computing environments are being more and more various due to the development of technologies. While existing computing environments used for fixed locations or particular purposes by requesting big scale monitors or complicate calculation performance, recent computing environments are used for a variety of locations and for a diversity of purposes by using various devices. Because of the needs, digital device convergence, which emphases portability and mobility, came out. However, almost researches for user interface are performed for big scale monitors or complicate calculation performance until now. By the reason, user interface on each small device is different from others, or is not appropriate for the purpose of small device. Therefore, this research is to design Zoomable User Interface (ZUI) that adapts for small devices by adding the existing user interface on small devices and haptic technologies, and to implement a user interface for PDA devices.