Passivity theory is very useful for stability analysis of bilateral teleoperation. Many researchers use passivity-based stabilization method such as scattering theory or wave variables. However, passivity-based stabilization is too conservative to design a high performance teleoperation system. High performance means that human operators can feel high-accuracy reaction force from environments. In this paper, we analyze l2 stability of some bilateral control systems with communication delay using small gain theorem. This theorem is renowned as a stable condition of multi-input multi-output feedback systems. And a novel control architecture which satisfies l2 stable condition of the theorem is proposed. The proposed control system has four communication channels. The validity of the proposed control system is shown by experimental results.