There have been few epidemiological studies in China which have randomly selected subjects for examination. This study randomly selected 240 subjects aged 6 and 12 years from six schools in the Haidian District of Beijing, China. Examiners were calibrated and used standardised light sources and methods. Five per cent of the 6 year old children and 54 per cent of the 12 year old children were caries free. The dental caries treatment needs for 6 year old children were substantially greater in quantity and complexity than the needs of those aged 12 years. School based preventive and treatment programmes directed against the differing requirements of the age groups and supported by community-wide strategies for prevention appear as dental health matters of urgency in China.