Abstract: On the basis of three main school of multinational enterprises (MNEs) theories, i.e. monopolistic advantages (HKC), internalization (CAW), and resourcebased view (Penrose), some MA motives theories such as Monopoly theory, Efficiency theory, Growth theory, Valuation theory (or private information hypothesis), Process theory and Economic Disturbance theory are systematically introduced. It is argued, in this essay, although not giving out any exact theories, that updated researches mostly focused on neces...