Competition in activities related to the exploration and utilization of outer space natural resources has intensifi ed, but the traditional legal system of outer space is unable to meet the needs of practice. The insight from the “Coase Theorem” in Law and Economics suggests that clarifying the legal attribute of outer space natural resources as “res communis” and recognizing that international entities may assert claims to partial rights over them is a more practical and effi cient arrangement of rights. Compared with the pursuit of justice value in the traditional outer space legal system, some unilateral legislation and attempts of multilateral accords in recent years have been an over-assertion of efficiency value to meet the needs of practice. As a result of the reconciliation between the values of justice and effi ciency, the proposal of the “Priority Rights” for outer space natural resources may represent a potential shift in the value of the outer space legal system, but there are defi ciencies in the possibility of the abuse of rights and the increase of the cost of delimitation of rights. In order to achieve a balance between the values of justice and effi ciency in the process of arranging the attribution of rights to outer space natural resources, it is necessary to reaffi rm and strictly abide by the basic principles of international outer space law, optimize the connotation of the “Priority Rights” of outer space natural resources and promote the legalization of this concept.