We examined the potential mediating role of sex partner concurrency in explaining associations between experiences of homophobia and financial hardship and HIV risk behavior among a sample of 477 men who have sex with men (MSM) recruited in Shanghai, China from 2004 to 2005. We found significant positive direct associations of experiences of homophobia and financial hardship with having unprotected anal sex with men. These associations were not mediated by male partner concurrency. However, male partner concurrency had a direct effect on having unprotected anal sex with men. Male and female partner concurrency did not mediate the significant association between experiences of homophobia and having unprotected anal/vaginal sex with both men and women, but was positively associated with having unprotected anal/vaginal sex with both men and women. These results suggest that homophobia, financial hardship, and sex partner concurrency should be addressed to help reduce sexual risk for HIV among MSM in China.