Abstract 1. Analyzing from either the perspective of U.S. interest or superpower's responsibility for maintaining the regional security, the United States role of establishing cross-strait CBMs is critical and essential. 2. Although Beijing's leaders issued positive statement on the Taiwan Strait situation, PRC's military deployment against Taiwan had no significant change. This shows that PLA is using the military as a political bargaining chip and the unbalanced forces across the Taiwan Strait as a potential threat to Taiwan. 3. The relationship between Taiwan and the United States appears to have common interests with mistrust, For example, during the administration of the Green Camp (DPP), the mutual trust between Taiwan and the United States had quite some wear and tear. President Ma administration had made positive improvment with PRC government, but the cross-straitrelations with impression of over pro-China attitude also made the United States decision on arms sales to Taiwan into a careful consideration trend. 4. About the role of U.S. in the cross-strait relations, U.S. still controls the cross-strait competing and cooperation relations to obtain its own interests. Even though the relation between Taiwan and the United States remains unofficially close, the fact that U.S. interests from U.S.–China cooperation are far greater than those interests from US-Taiwan alliance should be paid of great attention, especially the U.S. has been concerning the PRC' growing military development as a threat to Taiwan. Therefore, cooperation instead of confrontation would be the future focus of U.S.-China-Taiwan relation.