The invalid contract system is one of the important research topics in the field of civil law in china. The Article 52 of The People’s Republic of China Contract Law has some rules about the invalid contract system, but there are still shortcomings in the invalid contract system. Therefore, this paper gives corresponding amendments and improvements to the Article 52 of The People’s Republic of China Contract Law on the basis of studying the cognizance criterion of invalid contract and discussing the problems related to the cognizance criterion of invalid contract.In this paper, the research follows the principle of problem for guide and the principle of discourse analysis for clue and has four parts to do some research:The first part summarizes the invalid contract system, and put forward that the main problem this paper has to solve is the cognizance of the invalid contract. In the second part, the author puts forward the view that the major problem of Article 52 in The People’s Republic of China Contract Law is the lack of unified criterion to cognize the invalid contract, and specific discusses the problem from the field of theory and judicial practice. In the third part, the author gives the answer to the above problem directly, that is whether harm the damage public interests or not should be the criterion to cognize the invalid contract. at the same time, the author analyses the reason why whether harm the damage public interests or not should be the criterion to recognize the contract is invalid or not from the angle of the view of value, the legislative intent and the economic development; Then, the author further discusses the recognition method of public interests, and puts forward the view that we can adopt the identification method of the legal characteristics, the identification method of the public interest categorization and the identification method of the reversed exclusion to solve the problem of the cognizance of public interests. At the same time, the author also explores the relationship between the national interests, the collective interests, the third party’s interests and public interests, and puts forward the view that the national interests, the collective interests and the third party’s interests belong to the category of public interests. In addition, the author also researches the relationship between the mandatory provisions violated the law and the administrative regulation and the public interests, puts forward the view that the dividing standard of the effective mandatory provisions and the administrative mandatory provisions is whether damage the public interest or not; The fourth part combines with the above argument, refactoring the status of the item 4 of article 52 of the Contract Law, and gives advises and suggestions about the revise of the Article 52 of The People’s Republic of China Contract Law. |