BACKGROUND: Insufficient sleep duration among university students was commonly associated with many detrimental effects. University students experience substantial environmental and psychological changes. Female and male university students may differ in many spheres. However, most research on sleep duration of university students is based on an aggregate sample rather than digging the sex-specific profiles. The objective of this study is to examine potential sex differences in the correlates of sleep duration and explore the underlying mechanism of correlations. METHODS: This is a large-scale university-based mental health survey, which was conducted in university students in Qinghai Province in Northwest China in December 2019. A multi-stage logistic regression was separately fitted by sex to examine the factors associated with short sleep duration in university students. RESULTS: A total of 5,552 university students with an average sleep duration of 6.88 h (SD = 1.04) were included, among which 35.0% of the participants may currently be sleeping less than the optimal duration. Female students (6.84 h, SD = 1.00) slept shorter than males (6.94 h, SD = 1.09). The only parallel between sexes was that both female and male students with 3-5 times weekly breakfast were less likely to have short sleep duration. Adjusting for depressive symptoms in the following step eliminated the association between anxiety symptoms and short sleep duration in the model for female students. Female-specific associated factors with short sleep duration were age, grade, academic pressure, weekly physical exercise, depressive symptoms. Male-specific characteristics were current smoking tobacco cigarette, self-perceived health, duration of daily Internet use. CONCLUSION: Characteristic profiles of sleep duration differed between female and male university students; only a few male-specific factors were identified. Psychological guidance and education courses as well as other interventions to improve university students' sleep and related health should be designed and implemented based on sex differences.< Réduire