In order to obtain vehicle longitudinal dynamic parameters for intelligent cruise control (ICC) fast and at a low cost, a parameter identification method based on vehicle longitudinal dynamic model was proposed. Five kinds of road experiments, including standing still, coasting in neutral gear, coasting with engaged gear, driving with constant speed and braking, were designed for data collection. A Kalman filter was designed for data preprocessing. Such vehicle longitudinal dynamic parameters as rolling friction coefficient, aerodynamic coefficient, switching line between throttle and brake control, brake efficiency factor and engine speed characteristics were identified by using least square method. A vehicle longitudinal dynamic model was calibrated by the acquired parameters; the validity of the proposed identification method was demonstrated by the perfect coincidence of experiment data and model output. 