Abstract:This paper introduces social network theory and new institutional theory in the research of new venture growth, takes new ventures in Pearl River Delta Region as research samples and conducts empirical analysis on whether and how alliance network mediate the relationship between alliance network and new venture growth performance. Research results show that new venture’s alliance network has positive impact on organizational legitimacy; organizational legitimacy has significant positive impact on growth performance; moreover, alliance network has significant indirect effect on new venture growth performance which is mediated by organizational legitimacy.