A simple yet more effective filtering algorithm for 3-D passive location systems is developed by combination of pseudo-linear filter with modified input estimation approach. In this method, the acceleration is treated as an additive input term in the corresponding state equation, and higher dimension pseudo-linear filter is used to solve the passive tracking problem of air target. The original state and acceleration vectors are estimated simultaneously with the higher dimension pseudo-linear filter. Simulation results show that the proposed tracking algorithm can operate in both the non-maneuvering and the maneuvering modes, and the maneuver detection procedure is unnecessary; passive sensor can track the maneuvering air target by using the proposed method.