In this paper, we propose a new ground-to-train communication system using mobile object tracking technique thinking that can realize enough transmission speed on the moving train. Based on the field experiments, we report our proposed system's effectiveness as the new high-speed ground-to...train communication system. We also propose the tracking control algorithm of beacon light using the wide-angle lens and the telephoto lens. This algorithm is used for mobile object's position acquisition in the proposed system. The wide-angle lens is used for acquiring the beacon light, and the telephoto lens is used for tracking the beacon light.