Abstract: Limited by the traditional legal doctrinal study, the disputes about the mode of property change in China have been difficult to resolve. The first mock exam is mainly about the legislative choice of single mode and mixed mode, creditor formalism and real right formalism. There are conflicts and contradictions between policy science and system theory in the study of traditional law dogmatism, and it is difficult for both sides to agree on the theory of property right change. There is no concept of property right in common law system, but instead of property right. Based on the micro perspective of law and economics, British and American law provides a perspective for the comprehensive understanding of the relevant theories of property change, and provides a research method for solving existing disputes. With the aid of the first mock exam, the single mode is in line with the basic law of economics of supply and demand of law and the innovation of legal system. Formalism is consistent with the basic law of economics, which is cost and benefit, safety and efficiency. The first mock exam is to combine the legal thinking and economic analysis. The two way is the single mode. Under the first mock exam, China's the first mock exam of real right is the best one. In the existing legislative context, the creditor’s formalism is the feasible way.