The paper presents the design process of controller for active suspension employed by vehicle based on the co-simulation. Firstly, a detailed multi-body dynamic model of the vehicle was established by using ADAMS/Car software package. Secondly, a fuzzy controller was designed for active suspension system based on genetic algorithm, then programmed by means of Matlab/Simulink. Finally, the co-simulations were carried out based on ADAMS/Car and Matlab/Simulink. The co-simulation model can simulate vehicle dynamic response with the control of ASS under random road and impulse road condition. Through simulation result analysis, it indicates that the co-simulation method is effective and feasible, and the experimental result indicates control method is applicable, too.