The target tracking performance of radar system is dependent on the accurate modeling of target motion and the suitable filter for treating the noise problems when the radar detects the target. In this paper, the line-of-sight (LOS) dynamic equations of the interceptor-target are modified to be the motion model of maneuvering target and that is combined with the extended Kalman filter to treat the noise during the target tracking process. Besides, the proposed method will be compared with the current statistical mode and the constant acceleration model. The simulation results show the proposed technique of target tracking has the best estimation precision. The required measurement information of target state can be detected by the radar system in this study so the developed algorithm is usable to work on the radar system for tracking a maneuvering target.