Today for higher marketability of products, a manufacturing system is required that can reduce production time and enhance product properties greatly. In order to implement the system, a computerized design-supporting tool is indispensable for the design and supply of optimized production processes with high product quality in a reduced lead time. The computerized tool can help minimize design errors so that the time for process design and the cost for conventional trial and error can be saved. In this study, the developed automatic forging die-design system can be divided into 5 main parts. These are forging process analysis based on rigid-plastic F.E.M., pre/post processor with user-friendliness on PC environment, process design expert system for cold and hot forging processes, establishment of the material database using the thermal deformation experiment, and standardization of forging dies and development of the automatic CAD technique. These 5 parts were integrated with common process and material database and main control window, the effective design of real forging processes.