Based on the resource-based view of the firm, the author studied the relationship between the resource an enterprise owned and its competitive advantage. The author thoroughly studied resource-acquire mechanism and competence-establish mechanism, and then put forward a model of core resource-based rent-acquire mechanism. The author thinks that the excess rent of an enterprise comes from the synergy of heterogeneous resource and competence. Organizational learning plays a key role in resource renewing and competence upgrading. The core resource-based rent-acquire mechanism is an important source of a firm's sustaining competitive advantage.