Since its inception, bilateral relations between the United States of America and China have changed over time. The two countries' bilateral relations emerged from the 1970s with 'ping-pong' diplomacy and there have been many pauses in their mutual relations. The United States and China cooperated in the economic and military fields and their mutual relations developed significantly until the late 1990s. The heads of the two states began to visit each other and economic ties were strengthened. tightened from year to year. However, issues of human rights and freedom of expression have weakened Sino-US relations. The US principle of promoting democracy and protecting human rights downplayed Sino-US relations after the Tiananmen Square events of 1989, with US Presidents George Bush and Bill Clinton playing key roles in determining American foreign policy towards China. To better understand the Tiananmen conflict and its influence on the future of American relations with the People's Republic of China, this article provides a brief history of bilateral relations until 1990. Historically, the United States and China did not did not have good relations due to the political regime of China. Additionally, China was not economically developed enough to maintain trade or relations of any kind with the United States. According to some historical data, the first Sino-US negotiations at the ambassadorial level began on August 1, 1955. Bilateral relations between America and China have several stages. The first stage of US-China relations began in 1971, when the two countries opened their doors to financial and economic ties. The trade volume of these countries amounted to US$4...... middle of paper ...... issues for the United States » NBR analysis, December 1990, http://www. nbr.org/publications/issue.aspx?id=143#.UpdHWcRdWGO8. Turner, Oliver, “Sino-American Relations Past and Present: Discourses, Images, Politics,” Political Perspectives 2011, vol. 5 (3), 27-45, http://www.politiqueperspectives.org.uk/wp-content/uploads/Sino-US-relations1.pdf9. Wang, Hui, “US-China: Ties and Tensions,” RAND Corporation, 257-288, nd, http://www.rand.org/content/dam/rand/pubs/monograph_reports/MR1300/MR1300.ch12 .pdf10. Yuan, Jing-Dong, “China-US Military Relations Since Tiananmen: Restoration, Progress, and Pitfalls,” Spring 2003, http://strategicstudiesinstitute.army.mil/pubs/parameters/articles/03spring/yuan.pdf11. Yan, Xuetong. “The Instability of Sino-American Relations,” The Chinese Journal of International Politics 3, no. 3 (2010): 263-292, http://cjip.oxfordjournals.org/content/3/3/263.full