A country’s foreign relations is composed of many different parts, and foreign aid is one of the most important components. For China’s diplomatic relations, foreign aid also plays a vital role in the overall diplomacy throughout its entire diplomatic history since 1949. However, foreign aid of China experiences the several changes in both theory and practice in the past 65 years, instead of remaining stereotypical. This article attempts to explore the causes of these changes of China’s foreign aid from the point of view of Constructivism, which stressed the importance of norm, identity and culture in international relations and diplomatic practice. In the article, the theory of constructivism would be used to explain how the identity, norm and other socially constructed factors affect the direction and structure of China’s foreign aid in different periods. Moreover, as a typical representative of China’s diplomacy, the study of foreign aid also help to understand the changes of China’s diplomacy in different periods