Introduction This study explores the preference for daily versus on-demand pre-exposure prophylaxis (PrEP) among men who have sex with men (MSM) in developing countries when both regimens are available. Methods From 11 December 2018 to 19 October 2019, we recruited MSM for an open-label real-world PrEP demonstration study in four major cities in China. Subjects selected their preferred PrEP (oral tenofovir/emtricitabine) regimen (daily vs. on-demand) at recruitment and underwent on-site screening before initiation of PrEP. We used logistic regression to assess preference for daily PrEP and correlates. Results Of 1933 recruited MSM, the median age was 29 years, 7.6% was currently married to or living with a female; the median number of male sexual partners was four and 6.1% had used post-exposure prophylaxis (PEP) in the previous six months. HIV infection risk was subjectively determined as very high ($>$75%) in 7.0% of subjects, high (50% to 75%) in 13.3%, moderate (25% to 49%) in 31.5% and low or none (0% to 24%) in 48.1%. On average, participants preferred on-demand PrEP over daily PrEP (1104 (57.1%) versus 829 (42.9%)) at recruitment. In multivariable analysis, currently being married to or living with a female was associated with 14.6 percentage points lower preference for daily PrEP (marginal effect = -0.146 [95% CI: -0.230, -0.062], p = 0.001); whereas the number of male sexual partners (marginal effect = 0.003 [95% CI: 0.000, 0.005], p = 0.034) and a subjective assessment of being very high risk of HIV infection (vs. low and no risk, marginal effect size = 0.105 [95% CI: 0.012, 0.198], p = 0.027) were associated with increased preference for daily versus on-demand PrEP. Among the 1933 potential participants, 721 (37.3%) did not attend the subsequent on-site screening. Lower-income, lower education level, lower subjective expected risk of HIV infection risk and younger age positively correlated with the absence of on-site screening. Conclusions MSM in China prefer both daily and on-demand PrEP when both regimens are provided free. Social structural factors and subjective risk of HIV infection have significant impacts on PrEP preference and use. The upcoming national PrEP guideline should consider incorporating both regimens and the correlates to help implement PrEP in China.