Objective: To understand the prevalence and pattern of abnormal uterine bleeding (AUB) among female medical college students in Shanghai，to provide a basis for menstrual health intervention for female college students. Methods: A total of 912 female medical students from a university in Shanghai were selected through cluster sampling. An anonymous questionnaire survey on menstrual history and related factors was conducted in March 2021. Results: The prevalence of AUB among female medical college students was 39.9%, with cycle disordered and non cycle disordered AUB of 24.7% and 15.2%, respectively. Among female college students with AUB, 21.7% had two or three abnormal menstrual symptoms. Multivariate Logistic analysis showed that sleep quality was associated with both types of AUB, and female undergraduates with poorer and poor sleep quality were at increased risk of both cyclic disordered AUB ( OR =2.05) and non cyclic disordered AUB ( OR =2.00). Low BMI ( OR =1.66) and weight gain and loss ( OR =1.76) were associated with cycle disordered AUB. Frequent insomnia ( OR =2.45) was associated with non cyclic disordered AUB( P <0.05). Conclusion Abnormal uterine bleeding (AUB) is common in female college students, female medical college students with AUB have multiple concurrent abnormal bleeding patterns. Factors associated with AUB varied according to the type of AUB, with sleep quality correlates with both types of AUB.