Though there have been so many studies on management for stakeholders, this paper, from another perspective, applies management for stakeholders to the core issue of the strategic management - why do some enterprises have a better performance than others. Through introducing the concept of stakeholder utility functions, this paper deeply explores the relationship between management for stakeholders and competitive advantage, and explains why management for stakeholders becomes the source of competitive advantage. Finally, the author concludes that the management for stakeholders could facilitate enterprises to have more effective corporate governance mechanisms, form enterprises cluster and face the unexpected environmental changes more easily.