OBJECTIVE: To study the sleep quality and quantity and their influencing factors in Uigur and Hui children in Xinjiang Province. METHODS: From March to December of 2007, 912 Uigur and 1019 Hui school children (6 to 14 years) were randomly sampled from 6 cities of Xinjing Province. The questionnaire on children′s sleep states and sleep environments was filled in by children′s parents. RESULTS: The mean sleep time of Uigur and Hui children was 10.1±1.4 hrs. The sleep time in Uigur children was significantly less than that in Hui children (9.7±1.2 hrs vs 10.4±1.5 hrs; P<0.05). The mean incidence of sleep disorders was 23.56%. The Uigur children had a lower incidence of sleep disorders compared with the Hui children (18.42% vs 28.16%; P<0.001). Ethnic group, sleep latency, use of a swing bed, family history of snore, watching TV before sleeping, hypertrophy of tonsils, eating before sleeping, feeding patterns and recurrent upper respiratory tract infection were the factors associated with the sleep quality and quantity. CONCLUSIONS: The influencing factors of sleep quality and quantity are multifactorial in Uigur and Hui children in Xinjiang Province. Pediatrician, child health care doctors and parents should pay more attention to children's sleep. The incidence of sleep disorders is different between Uigur and Hui children, suggesting that more research for the prevention and treatment of sleep disorders should be performed in different ethic groups.