Abstract: Human exploitation of outer space resources is actually to extend human’s infinite desire for resources to outer space. Defining the legal attributes of outer space resources is the starting point of research on outer space resources exploitation. The legal attributes of outer space resources are classified based on whether human beings are greedy or not. If the human nature is “not greedy”, the legal attribute of outer space resources is judged as “common heritage of mankind”, while the legal attribute of outer space resources is judged as “res nullius”, if the human nature is greedy. After exploring the Chinese and western origins of the propositions of “common heritage of mankind” and “res nullius”, the paper clearly defines the connotation of these two propositions in the context of outer space, analyzes in-depth the current situation of the application of these two propositions in the field of outer space, discusses the applicability issue of the two propositions in China’s relevant system construction and practice, and evaluates the two propositions. In addition, it puts forward China’s position on the legal attributes of outer space resources. China should adhere to the proposition of common heritage of mankind, that is, “peaceful exploitation and utilization of outer space resources” “common ownership of outer space resources by all mankind” “responsibility of all mankind for the exploitation and utilization of outer space resources” and “cooperative” governance of outer space resources exploitation and so on.