[Objective] Two cognitive tendencies were implied in the study of land carrying capacity(LCC), they are, the limiting factor theory and the multifactor comprehensive theory. Based on the methodology review of these two types of research, two laws of LCC were refined, which could enrich the theoretical system of carrying capacity and serve the social practice better.[Methods] Methods of documentation and comparative analysis were employed.[Results] In the lights of the ideas of "the Law of the Minimum", "the Principle of Limiting Factors" and "the Cask Theory", we presented the first law of LCC, which reveals the fact that in a relatively closed man-nature system, the LCC depends on the carrying capacity of the limiting factor exclusively. This law is mainly applied to such situations as "How many people can the Earth carry?", "How many people can a country support?" or "What is the supporting capacity of scarce resources in a particular region?". Under the guidance of holism and systematology, the second law of LCC says that in an absolute open man-nature system, the LCC is determined by the synthesizing effect of multiple factors. Situations like "the amount of regional comprehensive carrying capacity" and "the index of regional comprehensive carrying capacity" can adopt this theorem.[Conclusion] Each law explains different connotations of LCC, which means the laws are appropriate for various circumstances respectively, and can meet different research purposes. When applying the two laws of LCC later, such problems as the maximum attribute contained in the LCC, or the relationship between the spatial scale and the laws need to be studied in addition to the prerequisites.