When the vehic1e is tracked by a radar with known geometrical position，the relative bearing and elevation can be measured by angle sensor installed on the vehic1e，and the relative height data can be obtained by radio or laser altimeter. According to these data，the vehic1e position can be determined. In order to raise the accuracy of position location，Extended Kalman Filter is utilized. The obtained position parameters are transformed to the flight path plane coordìnate system，The results from computer simulation are satisfactory.