Abstract: Paragraph 2 of Article 52 in the Criminal Procedure Law is the legal ground for the application of administrative law enforcement evidence in the criminal procedure. To understand the application of this article， it is necessary to pay attention to the realistic necessity， and the legitimacy of the substantial law， procedural law and evidence law should also be demonstrated. For the substantial law， there are intersections between the adjusted objects of administrative law and criminal law， and the social harmfulness of administrative violations and crimes is different. Therefore， the identification of important cases is common. For the procedural law， the accountability mechanism in China is dualistic， which means the corpus delicti is detected from the administrative enforcement. When the violation of laws is overlapped with crimes， the criminal process will be brought forward. For the evidence law， the scarcity of resources and the relevance of evidence should be proven. The connection and application of the administrative and criminal evidence is Chinese-specific， which is unnecessary abroad for the integral accountability mechanism is applied in their evidence system. In order to connect the legal legitimacy with the procedural legitimacy， the administrative procedure should be distinguished from the criminal procedure and the judicial power should be guaranteed by adhering to the bottom line of procedural justice.

Key words: administrative law enforcement evidence, criminal evidence, legal legitimacy