Abstract: Objective To study the prevalence and the risk factors of sleep disorders in preschool children in Wuhan.And to provide evidence for the prevention and intervention of sleep disorders.Methods 3 460 children aged 3 to 6 were enrolled into this study by using a stratified cluster sampling method in Wuhan.Parents of the children were surveyed with a question-naire.Results The mean total sleep time per day was(10.04±1.82)hours on weekdays(Monday to Friday),and(10.13 ±2.09)hours on weekend.The prevalence of sleep disorders was 52.95%,among which the prevalence of night awakenings was 27.43%,bruxism 23.22%,sleep-onset disorders 21.96%.Watching TV too late,adenotonsillar hypertrophy,parents' depression and anxiety,the frequency of coffee were the risk factors related to development of sleep disorders.Conclusion The total sleep time per day is relatively less and the prevalence of sleep disorders in children aged 3 to 6 in Wuhan is higher than that of other children,which merits a good attention.