As the international competition is becoming increasingly fierce, more and more countries, especially the developed countries frequently resort to protectionism to protect their domestic production and safeguard their own interests. The resurgence of protectionism exacerbates a variety of trade frictions and seriously damages the economic interests of countries all over the world. The bilateral trade between China and the US has great significance for the two countries to develop the productive forces, adjust industrial structure and achieve industrial upgrade. However, American protectionism towards China is becoming increasingly prominent in the recent decades, and the forms of Sino-US trade frictions are various. It not only hinders the development of Sino-US economic and trade relations, but also has adverse effects to the Chinese industrial structure upgrade and development of economic stability. In recent years, China-related economic and trade motions keep increasing in the US Congress. Trade disputes, such as issues of RMB exchange rate, intellectual property rights and Chinese export controls, etc. always exist in the Sino-US trade relations. The US trade policies towards China is also becoming the main reason of the Sino-US trade disputes, while its intention of the politicization is increasingly obvious and has great impacts on the Sino-US economic and trade relations. In the decision-making system of US trade policies towards China, interest groups play a iv very important role. Therefore, researches on the reasons why the US adopts protectionism policy towards China still have great significance. After doing some researches on previous studies on this topic, this paper attempts to access analysis to American protectionism policy towards China from the perspective of Interest Group Theory integrating international political economy. With the understanding of Sino-US trade and the overview of protectionism, cases studies will be applied for analysis. Specifically, through the cases studies of Sino-US textile trade frictions and the “special safeguard” on tyres, it will bring out causal analysis of American protectionism towards China based on Interest Group Theory and mainly focus on how the interest groups influence the decision-making of American trade policy