Objective: To analyze the situation of AIDS knowledge and discrimination among freshmen in Chengdu city, and to explore possible effects of AIDS knowledge on discrimination. Methods: A cluster random sampling was employed to investigate 1 053 college students from 11 universities in Chengdu about their HIV/AIDS knowledge and discrimination. The scores of AIDS knowledge and discrimination of students with different characteristics were analyzed, and the influence path of AIDS knowledge on AIDS discrimination were further analyzed based on different peer relationships. Results: The total scores of AIDS knowledge was negatively correlated to AIDS discrimination( r s =-0.13, P <0.01). After adjusting for confounding factors, the total score of AIDS knowledge was associated with the total score of AIDS discrimination( β =-0.12, P <0.01). AIDS knowledge played a role in AIDS discrimination in intimate, general and unfamiliar peer relationships, with standardized path coefficients of -0.20, -0.24 and -0.18 respectively( P <0.01). Conclusion AIDS knowledge are correlated with discrimination among freshmen under different peer relationships. More anti-AIDS discrimination courses should be added to AIDS education to reduce the students’ fear and stigma of HIV/AIDS patients and related risk groups.