According to the National Defense Authorization Act of Fiscal Year 2000, the U.S. Department of Defense began to submit a report on the military power of the People’s Republic of China to specified congressional committees. The annual report addresses the current and future development of Chinese military and security strategy and the security situation in the Taiwan Strait each year. Since 2000, the report has become one of the most authoritative official assessments of Chinese military development for the global strategic community. This paper reviews how the Pentagon assesses the trends of China's military development. Since the early 1990s, Taiwan has become the primary focus for the modernization of the PLA’s capabilities. In the 2006 report, the pace and scope of China’s military modernization was shown to already exceed Taiwan’s contingency planning The 2019 report indicates China is implementing a comprehensive military modernization program aimed at making the PLA a “world-class” military force by 2049. In addition, the paper also presents the focus of China’s military and security development in each annual report, such as joint operations developments, anti-access/area denial capabilities, overseas military presence, missiles and air defense and energy strategy. However, each annual report always demonstrates that the U.S. is determined to maintain peace and stability in the Indo-Pacific region to achieve its strategic goals.