Objective To understand the medical college students' knowledge,attitude and behavior of AIDS,and provide the basis for health education programmes.Methods 2 130 school students were recruited by cluster sampling method in one medical college,including 717 freshman,533 sophomore and 880 junior.Questionnaire was used to investigate AIDS-related knowledge,attitudes and behaviors to all of the 2 130 students.Results The correct answer rate was 80.72%,which was positively correlated with the grade,but the knowledge of non-AIDS transmission and detection techniques was still not very clear,such as mosquito bites,sharing towels and clothing with AIDS patients could spread the AIDS or not,the correct answer rate was just 36.7% and 54.3%.There was a certain attitude of discrimination in medical students on AIDS,79.9% of medical students were unwilling to shopping at the place of AIDS patients,and 76.4% were unwilling to have dinner with AIDS patients.Compared with the freshmen,high-grade students have higher knowledge level on HIV/AIDS,but their attitude to AIDS patients was poor.Conclusions Presently,medical students' recognizing on HIV/AIDS still have a long distance from the professional requirements,suggesting that AIDS health education in medical college students is necessary.