A control algorithm using the extended Kalman filtration(EKF) to estimate the vehicle state was suggested.The algorithm based on a 3-DOF nonlinear vehicle model was applied to estimate the yaw rate,the longitudinal velocity,and the ride slip angle of the mass center in the vehicle driving.The estimated vehicle state parameters were compared with the results from the vehicle field test.The comparison demonstrated that the EKF based algorithm can estimate quite accurately the above-mentioned vehicle driving state parameters.