A Hardware-In-The-Loop Simulation(HILS) is widely used in the test and evaluation(T&E) of complex guidance and control systems hardware for aerospace applications. The real time HILS was performed by using a Taxis flight motion simulator, real time computer, I/O system and flight control system hardware along with a flight trajectory of the guidance flight system. In this paper, we proved the validity of the proposed simulation method, real time HILS, in the guidance night system by comparing its simulation results with the software simulation results.