A total of 2432 primary school children, aged 7-14 yrs. in urban areas of Beijing, were evaluated with the Children's Behaviour Questionnaire developed by Rutter. The frequency of behaviour problems in primary school was 8.3%-7.4% antisocial behaviour and 0.62% neurotic behaviour. Behaviour problems were higher in boys than girls: antisocial behaviour was dominant in boys, while neurotic behaviour was common in girls. The frequency of behaviour problems varied significantly with the different social environments in which the children were brought up, but were not different between one-child families and those with more children.