Sleep plays a key role not only in children's physical growth, behavior, and emotional development, but also in cognitive functioning. The present study was designed to survey the sleep characteristics and to examine the associations between sleep characteristics and child-reported sleep quality in urban school-aged children of China. A random sample of 19,299 children aged 5.08 to 11.99 years old, 49.7% boys and 50.3% girls with a mean age of 9.00 years old, participated in a cross-sectional survey which was conducted in 8 cities of China. A parentadministered questionnaire and the Chinese version of the Children's Sleep Habits Questionnaire were co mpleted to quantify family and personal information and to characterize sleep behaviors. The mean sleep duration was 9.17h (SD=0.80) on weekdays and 9.80h (SD=1.06) at weekends. Sleep problems were commonly existed with a relatively high prevalence ranging from 14.5% for sleep-disordered breathing to 75.3% for daytime sleepiness. There were significant gender and age differences existed in sleep problems. Various kinds of sleep problems and unhealthy sleep patterns were associated with poor sleep quality in Chinese school-aged children. The mean sleep duration was less than the recommended 10 hours per day for school-aged children. Sleep problems were commonly existed, which was beyond our expectation. Sleep problems and unhealthy sleep patterns were harmful to children's sleep quality. A longitudinal study is needed to investigate the trends of sleep behaviors and the relative factors including personal lifestyle, family and social environment so as to intervene and improve children's sleep quality.