Abstract: A new algorithm for NLOS(Non-Line-Of-Sight) passive acoustic localization of low altitude targets is presented. Based on target reflection point, the target point can be localized. This approach can reduce the NLOS error caused by acoustic propagation effectively, to increase localizing precision and provide important information for the radar to track and localize. Simulation results show that the algorithm have good effectiveness to estimate the low altitude targets position especially which hiding behind a mountain when time-delay estimation is high enough.