A pattern generation system based on an object-oriented pattern knowledge representation method developed previously in Zhejiang University is introduced. We evaluate the effectiveness of this system from authorsi current new research perspective in the Design Technology Research Centre of the Hong Kong Polytechnic University. We then put forward a new platform model to support graphical pattern design emphasising ethnic minority culture. The purpose of building this new platform is to increase the ability of the system in supporting collaborative design. New methods are developed for representing patterns as well as the knowledge about how they can be reused in design applications. In this paper the method for element dynamic classification, knowledge representation of pattern design and the system architecture are introduced.