Text Box: AN EPIDEMIOLOGICAL STUDY ON SLEEP CHARACTER-ISTICS IN CHILDREN FROM BIRTH TO 5 YEARS OF AGE IN CHINA Jiang F, Yan C-H, Wu S-H, Shen XM Xinhua Hospital, Shanghai Second Medical University, Shanghai, China Objective: The current survey is an attempt to assess age-specific sleep characteristics and prevalence of sleep problems in children from birth to 5 years of age in China, and to identify related factors for sleep characteristics and sleep problems. Method: The questionnaire about children's social environment and sleep condition was based on children's sleep physiological character-istics and the International Classification of Sleep Disorders. After the questionnaire was tested the validation, the parents of 3266 0-5-year-old children randomly selected among the 5 districts in Shanghai were given the questionnaires about children's sleep and their social environment. Results: Of the 3266 questionnaires, 3195 were completed and could be used for statistical analysis. The total sleep time duration of children below 48 months in China was less than that of the same age in other western countries and the percentages of the sleep problems of 2-5 years children (57.26%) was also higher. The factor related to the total sleep time were parental insufficient sleep, children's difficult temperament, parental presence at sleep onset time, while the high-risk factors for sleep problems were parental sleep problems, children's difficult temperament and health problems, changing the sitter frequently. Conclusion: The total sleep time of 0-5-year-old children in China was less and the prevalence of sleep problems of young children was also higher compared to the existing data, which merits a good attention. 1167