The behavioral problems of Chinese children were examined in a questionnaire study of a representative sample of 3,069 seven-year-old Chinese schoolboys in Hong Kong using Rutter's questionnaires for completion by parents and teachers. Separate robust dimensions of hyperactivity, antisocial, and neurotic behaviors were evident. The correlations among different dimensions were similar to those reported in the West. Short-term longitudinal analysis suggested that these dimensions were stable over time and that antisocial behaviors might develop in hyperactive children. The finding highlights the necessity of differentiating the hyperactive domain from the antisocial one. A significant source effect was found in all three dimensions. Chinese schoolboys had nearly two times the level of questionnaire-rated hyperactivity compared with school boys in the West; but it is premature to conclude that hyperactivity is more common in Chinese schoolboys in Hong Kong. Cross-cultural differences in adults' expectations and tolerance remain a plausible explanation.