BACKGROUND: Increasing human immunodeficiency virus (HIV) testing is critical for HIV control. This study aimed to evaluate the interaction between social norms and self-efficacy on HIV testing among Chinese men who have sex with men (MSM). METHODS: We conducted an online survey in eight Chinese cities in Shandong and Guangdong Provinces in July 2016. We included participants who were born as a male, at least 16 years old, currently living in one of the designated cities, and had ever engaged in anal sex with a man. We collected information regarding socio-demographics, high-risk behaviors, and history of HIV and other STI testing. We coded sensitivity to social norms using six items asking participants about their perceived social norm regarding HIV testing. We coded HIV testing self-efficacy using a separate six-item scale. We interpreted higher mean scores as higher sensitivity to social norms and higher self-efficacy, respectively. We conducted logistic regressions to evaluate the interaction between self-efficacy and social norms on HIV testing. RESULTS: A total of 2105 men completed the survey. The mean age of the participants was 25.97 ± 6.42 years. Over four-fifths (85.9%) of participants were unmarried, 22.7% were students, and 64.6% at least had a college degree. 62.5 and 32.6% of participants ever and tested HIV in the last three months, respectively. With respect to uptake of HIV testing in the last three months, the adjusted odds ratio was 1.01(95% CI: 0.96-1.06) for higher sensitivity to social norms and 1.09 (95% CI: 1.05-1.14) for higher self-efficacy, with an interaction effect of 1.02 (95% CI: 1.01-1.03), respectively. With respect to uptake of lifetime HIV testing, the adjusted odds ratio was 1.03(95% CI: 0.99-1.07) for higher sensitivity to social norms and 1.15 (95% CI: 1.11-1.19) for higher self-efficacy, with an interaction effect of 1.02 (95% CI: 1.01-1.04), respectively. CONCLUSIONS: Our survey demonstrated that there is a significant association between the uptake of HIV testing with sensitivity to the social norm, higher self-efficacy, as well as the interaction between them. Tailored studies for improving HIV testing among MSM in China can combine these two interventions together.