Abstract: The formation of Dependency Theory is primarily due to the fact that the practice of Modernization Theory met with failure in underdeveloped countries and that this failure brought to Modernization Theory an extensive criticism. It also owes its formation to Latin American economists' studies in theory. Its theoretical sources are mainly thoughts of the classic writers of Marxism, such as Marx, Lenin and MAO Ze-dong, etc., and that of the modern radical economist F. List.