Previous research has documented the deleterious impact of homosexuality stigma on HIV sexual risk behavior among men who have sex with men (MSM) and the vulnerability of this group in China for HIV acquisition. Factor analysis of 10 survey items from 477 MSM from Shanghai yielded two factors: Perceived stigma assessed participants' impressions of the degree of societal stigmatization of homosexuals whereas enacted stigma measured direct personal experiences of stigmatizing behaviors. Enacted stigma exhibited satisfactory internal reliability and was associated with HIV sexual risk behavior. Further research is needed to refine perceived and other stigma constructs for Chinese MSM.