Abstract: In order to improve the automobile ride comfort and handling stability,a nonlinear three-freedom handling stability model was established and the influence of the load transfer and the tire nonlinear stiffness characteristic on the automobile stability was researched during the high speed lane-change condition.An optimization of the suspension parameters based on genetic algorithm was proposed.The vehicle body roll angle was selected for minimum optimization objectives,the suspension frequency and the vehicle understeer performance was selected for constraint condition,and the suspension stiffness parameters were taken as the the design variables.The computation results show that the suspension design scheme through optimization has apparant effects on improving ride comfort and handling stability.Finally,the result of analysis indicates that the ride comfort and handling stability during high speed can be improved effectively through this matching method.