Since the end of the cold war, the obstacles between the national relationships have been eliminated gradually. The trend of economic globalization swept through the world. The exchange and collision between different cultures are more frequent and close. Along with the rapid development of information technology represented by network technology and the wide application of modern means of transport, international system gets into a global and modern stage. The social interaction and personnel exchanges between the countries more and more become the main content of international politics and international relations. Under this background, the public diplomacy is booming in the worldwide, becoming the important feature in the new century between international communities and national communications. Based on the above background, this paper tries to analyze public diplomacy from the perspective of soft power in China's diplomacy and the national development. In the meanwhile, it focuses on China's public diplomacy towards the United States, to explore the public diplomacy's achievements and the insufficiency. This paper hopes to help fully understand the Chinese diplomacy, and the progress, potential, and difficulties in the process of China's rise.