ABSTRACT: Objective:The outbreak of the 2019 novel coronavirus disease (COVID-19) not only caused particularly large public health problems, but also caused great psychological distress, especially for medical staff. We aimed to investigate the prevalence rate of insomnia and to confirm the related social psychological factors among medical staff in hospitals during the COVID-19 outbreak. Method:Medical staff members in China were recruited, including frontline medical workers. The questionnaire, administered through the WeChat program, obtained demographic data and asked self-design questions related to the COVID-19 outbreak, insomnia/depressive/anxiety symptoms, and stress-related symptoms. We used a logistic regression analysis to examine the associations between sociodemographic factors and insomnia symptoms. Result:There were a total of 1,563 participants in our study. Five-hundred-and-sixty-four (36.1%) participants had insomnia symptoms according to the Insomnia Severity Index (ISI) (total score ? 8). A multiple binary logistic regression model revealed that insomnia symptoms were associated with an education level of high school or below (OR = 2.69, p = 0.042, 95% CI = 1.0-7.0), being a doctor (OR = 0.44, p = 0.007, 95% CI = 0.2-0.8), currently working in an isolation unit (OR = 1.71, p = 0.038, 95% CI = 1.0-2.8), is worried about being infected (OR = 2.30, p < 0.001, 95% CI = 1.6-3.4), perceived lack of helpfulness in terms of psychological support from news or social media with regard to COVID-19 (OR = 2.10, p = 0.001, 95% CI = 1.3-3.3), and having very strong uncertainty regarding effective disease control (OR = 3.30, p = 0.013, 95% CI = 1.3-8.5). Conclusion:Our study found that more than one-third of the medical staff suffered insomnia symptoms during the COVID-19 outbreak. The related factors included education level, an isolation environment, psychological worries about the COVID-19 outbreak, and being a doctor. Interventions for insomnia among medical staff are needed considering the various sociopsychological factors at play in this situation.