Previous studies suggested a rapid increase of HIV prevalence among men who have sex with men (MSM) in China in recent years, from 0.4% in 2004 to 5.8% in 2006. However, some MSM had never been tested for HIV. In order to expand the accessibility to HIV testing, understanding HIV-testing behavior and barriers among MSM is important. Using data collected from 307 young migrant MSM (aged 18-29 years) in 2009 in Beijing, we aimed to identify psychological and structural barriers to HIV testing. MSM were recruited through peer outreach, informal social networks, Internet outreach, and venue-based outreach. Participants completed a confidential self-administered questionnaire. Results show that about 72% of MSM ever had an HIV test. Logistic regression analysis indicated that the HIV-testing behavior was associated with sexual risk behaviors (e.g., multiple sexual partners and inconsistent condom use for anal sex) and history of sexually transmitted diseases. Eighty four MSM (28%) who never had an HIV test reported that the psychological barriers mainly were perceived low risk of HIV infection and fears of being stigmatized. The structural barriers reported inconvenience of doing test and lack of confidentiality. Future HIV prevention programs should be strengthened among MSM to increase their awareness of HIV risk. Efforts are needed to increase access to quality and confidential HIV testing among MSM and reduce stigma against MSM.