Objective To explore the acceptability of male circumcision (MC) as an HIV prevention method and its related factors among young men of Yi ethnicity in Liangshan prefecture. Methods 446 young men were selected in Butuo county,under stratified sampling method. Using a self-designed questionnaire,face to face interviews were taken to collect HIV-related risk behaviors,knowledge and acceptability of MC. Results After an introduction on MC by interviewers,40.6% of the interviewees expressed their willingness in taking this surgery. The main reason for acceptance was that they felt this surgery might reduce the risk of HIV infection (90.1%). For those who refused to take this surgery,most of them thought it was too sensitive and embarrassing (52.5%) and were afraid that it might affect their procreation ability. Data from logistic regression analysis indicated that the acceptability of MC was associated with the following factors as: age,income,experience of commercial sexual behavior. They also felt that messages related to male MC surgery could reduce the risk of being infected with HIV/STDs or induce pain when having sexual intercourse,or it might cause partial infection after surgery,or they might be mocked at if taking the surgery. Conclusion It is the prerequisite in helping young people of Yi ethnicity to have a good understanding on MC as for Yi people,embarrassment attitudes towards sex appears to be one of the big obstacles against the popularization of this surgery. The operation should be provided by trained and professional doctors,with standardized procedure,in good sanitary conditions and free for service.