The evolution of the information technologies like computer and the Internet has been largely affecting military technology area. It has been changing warfare aspect a lot, and greatly improving high-tech fighting power as well. This study proposes a way to construct and operate the synthetic theater of war in order to improve the national military combat training, based on the emerging concept of it. This paper first studies the component technologies of the L-V-C(Live Virtual Constructive)-based synthetic theater of war simulation system that enables the military training to be as similar as in the real combat field, and defines the various variables that can make effective use of the IEEE standard HLA/RTI. By doing that, this paper proposes an interoperable scheme that is suited to L-V, V-C, and L-C interoperation.