The article 5 of the Chinese Real Right Law is about the principle of Numerus Clausus.Literally,the "law"in this article means legal rules,which is ambiguous,and in this way the interpretation could be more flexible. We found that it’s possible to make a relaxed Numerus Clausus through the system interpretation,history interpretation and comparative law interpretation. The observation of life needs,practice of dealings and the type perspective manifested that the strict Numerus Clausus is incomplete,so the Numerus Clausus principle is able to and should be made a relative relaxed interpretation.To be concrete,the "law"of Numerus Clausus Principle could be laws,administrative regulations and judicial interpretations,but the customary law is not included. We should recognize that with the consideration of practice and dealings needs,the court could decide the quasi real right. We could make judicial interpretation or amend the law to deal with it when we have enough experience. Meanwhile,it’s necessary to stick the boundary line. There are five criteria could be follow in the process,de facto criteria,formal criteria,substantial criteria,necessity criteria and exclusion criteria.