A strategy for optimal design of train airconditioning condenser (TACC) was developed using genetic algorithm (GA).According to different design requirements the weight or the volume of TACC was taken as an objective function and the dimensions of spacing and thickness of the fins as the optimization parameters.The optimization results show that the weight(volume) of TACC is reduced obviously and the heat transfer performance is improved.The design requirements of high performance and light weight can be satisfied,when the train speed is raised.