Abstract: The thesis analyzes the mechanism of fraud decision-making on the foundation of prospect theory and cognitive bias,using questionnaire survey to investigate fraud tendency,the respondents including managers of the organization,financial workers and students who will be engaged in such kind of work. The outcome of statistical analysis makes it clear that the four types of cognitive bias(anchor and adjustment,availability,representative,and over confidence) will strengthen decision-maker’s tendency of fraud;In comparison with the respondents who have already engaged in work,cognitive bias have more effect on student respondents,especially on the aspect of weighting function.