The embedded training system(ETS) generates virtual combat environment containing virtual target, virtual threat, and virtual weapon. ETS enables participants to exercise air-to-air or air-to-ground combat training minimizing flight safety problem and maximizing cost and time effectiveness. The key function of embedded training system is virtual target generation, because other functions are based on virtual target data. Full function of virtual target simulation is the generation of aerial maneuvering, ground fixed and moving target containing actual target characteristics for training effectiveness. For the first development stage, virtual air-to-air target is necessary for missile and gunnery training. The reality of target maneuver increases the operating skill of trainee pilot. Thus, in this paper, the basic concept of virtual target simulation is studied to implement the embedded training system to avionics system.