Abstract: Objective To investigate the caries status of the population of all ages in Qinghai province and as a baseline data of dental incidence, thus to provide scientific basis for the establishment of oral health care. Methods Referring to the guideline for the 3rd National Oral Health Survey, the method of multistage, stratified, equal capacity, simple random sampling was first carried out in population included subjects aged 5, 12, 35- 44 and 65- 74 years in Qinghai province. Results The prevalence rate of deciduous teeth dental caries in 5- yearold children was 71.63% and dmft was 3.30. The prevalence rate of permanent teeth dental caries in 12, 35- 44 and 65- 74 years old people was 22.63%, 64.47% and 73.89% respectively. The mean number of permanent teeth dental caries in 12, 35- 44 and 65- 74 years old was 0.40, 2.06 and 3.08 respectively. The prevalence rate filled rate of teeth in the four groups was 1.85%, 2.53%, 8.00% and 3.47% respectively. Conclusion The result shows
that caries situation in Qinghai population is not optimistic, and the filling rate of dental caries is very lower. Therefore, oral health education activities should be strengthened. We must take effective measures to reduce the caries prevalence in Qinghai population and to increase the filled rate of caried teeth.