This research used the GPS Build-2 receiver to obtain the doppler frequency shifts of satellites first, and then sets up the simultaneous navigation equations. Finally, solves the receiver position coordinates as well as the local oscillator frequency by the least-squared-error method. The results obtained by using the Nortel STR-2760 GPS simulator, showed that the positioning accuracy is about one meter with four satellites' information. Therefore, the proposed positioning method is efficient for the vehicle navigation despite in heavy multi-path environments.