The Moon Agreement is the most advanced and complete treaty in the outer space law system. It is the only treaty that foresees the development of lunar resources and the commercialization of space activities. The principle of common heritage of mankind is the most important clause in the Moon Agreement and the focus of its controversy. Since the conclusion of the Moon Agreement, it has not been widely recognized. In recent years, the lunar activity has become more frequent, the economic attributes of the lunar activity have been continuously enhanced, the subjects have become more diversified, and the development of lunar resources is about to be feasible. The new situation poses new challenges to the Moon Agreement. In this case, it is imperative to re-examine the Moon Agreement.