The goal of the current work is to analyze the reasons that favored the approximation between the USA and China during the 1970 s, time in which both faced internal and foreign debilities, and also to approach in which way the relation between these nations contributed to the advancements of the Chinese development. As a way to substantiate the proposed objective, it will be used the World-System perspective s theoretical embasement describing the hierarchic position occupied by USA and China in the system. According to Wallerstein and Fiori, this relation varies in agreement to each Country s position in the international division of labour. At this time, we live in a capitalism World-Economy characterized by a complex and a competitive system, in which, the main power, in a moment of contraction, recreates its own competitor in search of alternatives that favours the reminiscence and expansion oh this power. This context enables the occurrence of productive reallocation in the system that for many times ends up favouring its own competitor, created by the main power. It is over this situation that is built a complementary relationship, commercial and economic, between the USA and China, since 1970 s.