The thesis mainly discusses the trade surplus in China, including its background, and the causes. At the same time, I concluded several questions: Why does China has such a big trade surplus, while other developing countries could not? How does its effects on other countries? Is it positive or negative? Based on trade policies and economic strategies, what can explain the causes of Chinese trade surplus? Is it good to maintain a trade surplus and bad to maintain a trade deficit for country? Whether the rest of world should worry about it, in particular, the US? The objectives of this essay are answered and discussed those problems, in view of several literature, theories and available data.