The essence of the core competence of a firm is knowledge, while organizational learning is the source of the formation of the core competence. Firstly, a "capability tower" diagram is built to illustrate the relationship among the organizational learning, core competence and the competitive advantage. The intermediate mechanisms outlined the core competence's formation are revealed. The underpinning role of the coordination and integration in the process is emphasized. Next, another diagram is employed to translate the learning mechanisms into details. Three different learning loops toward acquiring the core competence are analyzed, which are routine learning loop, capability learning loop and strategic learning loop.