Abstract: The multi-agent system architecture offers a supporting framework for cooperative work and sharing resources among designers,while the tree structure based genetic algorithm provides a tool for extending the thinking space of designers.The process of evolutionary design is illustrated by a mobile phone design example,which uses genetic algorithm based on the binary mathematical expression tree and mathematical software tool MATLAB to form sketch shapes and a feature based product tree to generate component combination choices.Because the designer personally guides evolutionary process,the satisfying result can be generated quickly.