Abstract: By building models of control power of bilateral diplomacy and multilateral diplomacy, this paper calculates relative control of typical diplomatic spheres of China, and points out key things of China's diplomatic work. The result shows that in the bilateral diplomacy, control power of China is almost equivalent with Japan and Russia, slightly higher than South Korea, much higher than India, and Pakistan, but much lower than that of the United States. These state have a direct effect on bargaining power of China with these countries. Consider three-way diplomacy, in China - Japan - South Korea relations, China has considerable initiative, Japan is passive. In China-Japan- United States, China is passive. In the China -United States - Russia, cooperation between China and Russia make position of United States weakened. In China-India-Pakistan, the join of Pakistan greatly increase the control power of China. In quartet and even more relationship, cooperation of China and Russia is good for China.