Abstract: The criterion for judging the legality of temptation investigation is the core point of the theoretical research of temptation investigation, and the requirement of the investigation theory development. The concrete basic researches on temptation investigation, especially the agreement between its theoretical interpretation and Marxist philosophical ontology, epistemology, axiology and methodology, determines that the refinement of the criteria for judging the legality of temptation investigation has the basis of philosophy and criminal law. In the investigation practice, the establishment of practice mode that fits for the investigation law, can accurately present the practice program of "during investigation" and "after investigation", can guide investigators to accurately judge the legitimacy of temptation investigation in different stages. In terms of utility, the evaluation criteria of economic utility, social utility and moral ethics utility based on the factors of total effect and marginal effect, efficiency and justice, kindness and justice can further make a reasonable evaluation of the refinement of the legitimacy judgment criteria of temptation investigation.

Key words: criminal investigation, temptation investigation, legality judgment standard, subjective criterion, objective criterion