| As one important legal system of law of obligation in continental law system, unlawful cause prestation has normally been regarded as one kind of ill-gotten gains in system of civil law. However, being different from normal ill-gotten gains, unlawful cause prestation should not be asked for regaining in normal in order to negatively punish the act. For this reason, unlawful cause prestation is often called as the exception for ill-gotten gains. Though many exceptions of this principle has appeared in modern civil law, after comparing to many countries' legislations and deeply researching the principle, this thesis believes that the status of the principle as the basic mechanism to deal with unlawful cause prestation is firm, for it reasonably presents one kind of strict legal idea.The present confusing and unreasonable situation of our country in dealing with the case concerning with unlawful cause prestation all lies in the defect of the legislation, so the thesis holds that we must introduce the cause theory and performing mechanism of unlawful cause prestation in continental law system into our legislation, also, the thesis presents its suggestions and legislative design in order to establish and perfect our country's unlawful cause prestation rules.This thesis consists of four parts.Part one is the basis of the unlawful cause prestation. Firstly, it interprets the meaning of "unlawful", "cause" and "prestation". Then, it gives the meaning of unlawful cause prestation as the act that finally transfers the rights of the property to others on the basis of breaching the compulsory rules of the public policy and good morals; Secondly, after discriminating the unlawful cause prestation and normal ill-gotten gains, this thesis gets the components of unlawful cause prestation; Finally, this part makes some basic classifications and compares some countries' legislation of unlawful cause prestation.Part two discuss the current meaning of the continental law system's cause theory to our country. In this part, this thesis analyzes the historicalbackgrounds for the appearance of cause theory and evaluates the objective cause theory and subjective cause theory. Then, the thesis holds that cause should be defined as the unity of objective cause and subjective cause, also, though the status of cause as a positive role to the effect of civil acts has fad, its negative role is obvious till now, for it's limitation of the personal will by the public interest, and it is the require of the social-oriented trends. In addition, this part also holds that the introduction of cause theory and the rules of unlawful cause prestation is of great current meaning to our country after discriminating the unlawful cause, unlawful object and unlawful subject matter and analyzing their different effect of law.Part three analyzes the performing mechanism of unlawful cause prestation. There are two stages and reasons to be abused on unlawful cause prestation. The first one is the prestation on the unlawful cause, and the second one is the person who make the prestation intends to pursuit the shelter of the law on the grounds of his "ugly act" while he has not obtained the illegal benefits or fully fulfilled his unlawful intend. Owing to this, this thesis believes that returning the unlawful cause prestation can only punish the first stage and simply concern with the first reason of unlawful cause prestation, so it is a solution beside the point. In addition, taking the judicial cost into consideration, this thesis finally draws a conclusion that "unlawful cause prestation should not be taken back" should still be the basic performing mechanism for the rules of unlawful cause prestation.There are many exceptions in addition to the basic performing mechanism. However, form the view of legislative interest, they are all unity in the needs of fulfilling the legislative intend and public interest of unlawful cause prestation.Part four holds that our country should introduce the cause theory and the rules of unlawful cause presta... |