This paper views organizational control mechanisms which are adopted by the parent company as a crucial influencing factor of MNCs’ knowledge flow. It mainly discusses the relations between multinational expatriates and the knowledge flow within multinational corporations. The authors investigated 129 subsidiaries which are located in Shanghai by means of questionnaires. The result of study indicates that, under the social context of Shanghai, multinational expatriates in MNCs have great influences on the knowledge flows within MNCs; and especially, expatriation of managers facilitates the enhancement of level of the knowledge flows within MNCs notably.