An optimal self-tuning control algorithm ispresented for vehicle suspension design. The controller, incorporating a weighting conroller, state observer and parameter estimator, is desined according to linear optimal control (LQG) theory. Based on the updated estimates of vehicle parameters and states, and the adapted weighting parameters, the LQG controller provides the optimal set of gains over different operating conditions. The feasibility and effectiveness of the proposed self-tuning system was investigated andproved by simulation studies.