The Chinese security strategy in Asia-Pacific region has to be viewed from the angle of national strategy interest in the long term. First, China always puts the protecting national sovereignty, unifies integrated territory and security in first position. Second, the long history time, Chinese fundamental mission is to focus vigour for insists on putting economic construction as center of all, it is the objective raised by main contradiction of Chinese society of today, is a key problem in deciding Chinese fate. Third, China needs stability of domestic environment and peaceful international environment. Sixty years after World War Ⅱ, China and Japan are still in the shadow of the past. With a deep mistrust of Japan, China is wary of Japan`s military capabilities and Tokyo`s desire to be a political power, The strengthening of the security alliance between Japan and the United States and their cooperation in developing the MD systems have caused much concern in China. China has made efforts in forging a constructive relationship with Japan in the hope of enhancing its comprehensive national power and it will continue to do so in the foreseeable future. However, a series of challenges, including the history issue, military modernization, territorial dispute, the Taiwan issue, and nationalism, are likely to fuel strategic competition between the two giants in Northeast Asia.