Objective: To explore the associations between sleep duration and negative emotions among junior college students,and to provide reference for mental health promotion among college students. Methods: Cluster sampling method were used to select 2 524 freshmen from a college in Huainan, Anhui Province. Questionnaires were used to investigate general demographic characteristics, sleep timing, negative emotions and other information. The restricted cubic spline and multivariate Logistic regression were used to analyze the relationship between sleep duration and negative emotion among junior college students. Results: The prevalence of depressive symptoms, anxiety symptoms, stress associated symptoms were 19.41%(490), 28.2%(713), 9.9%(250) respectively．The prevalence of negative emotions was higher among boys(24.3%,34.0%,19.1%) than girls(18.7%,27.4%,8.5%). The differences between groups were statistically significant( P <0.01). After adjusting for confounding factors, sleep duration and negative emotions showed a non linear dose response relationship. Compared with the reference group(8-<9 h), sleep duration <7 h was significantly associated with an increased risk of depressive symptoms and stress symptoms, and <8 h was associated with an increased risk of anxiety symptoms. The additional sleep time on weekends ≥5 h was associated with negative emotions compared with the reference group(<1 h)( P <0.01). Conclusion Short sleep duration and extra weekend sleep are associated with negative emotions. Reasonable sleep schedule among junior college students might be helpful for the prevention and control of negative emotions.