Abstract: Firebrick mould design is a knowledge-intensive process guided by multiple empirical rules concerning the dimension control of semi-finished brick, heat treatment control and various production process requirements. An intelligent mould design system was developed to automate the mould design process. AutoCAD2000 and ObjectARX were taken as the geometric modeling platform and programming tool. Object-oriented technology was used to implement the modules of solid modeling, parametric design, and database management. When the designer inputs the required dimensions for a certain type of firebrick, this system can automatically generate solid models of all the six mould plates, namely two sides, two ends, top and bottom.