There have been continuous efforts for developing the automatic mechanical design system to increase the efficiency of the tedious design process. However, these efforts have been concentrated on single platform application. Hence, the developed systems have been available only in a designated place and time and have been difficult to modify. In this study a web-based design system is developed to offer more reliability and convenience without my restriction of time and place. The developed system is programmed based on Java, and the architecture of the system has object-oriented features of Servlet and JSP and is independent on my operating systems. The developed system has been applied to the initial design of multi-stage gear drives, but as the framework of the developed system is however quite versatile, its application to automatic design of my mechanical system or evaluation can be easily expected.