Objective: To explore the effectiveness of comprehensive oral health care to reduce the caries incidence for children with severe early childhood caries (s-ECC) in an urban area in China. Methods: A total of 357 children aged 3 to 4 years old and diagnosed with s-ECC were recruited in this randomised controlled, single-blinded clinical trial for 1 year. Children of two different kindergarten classes were enrolled in this study and randomly divided into a test group (205 children) and a control group (152 children). The test group received comprehensive oral health care, which included: oral health examination, oral health education, topical fluoride application and dental treatment, and the children in the control group only received the oral health examination. The evaluation of the oral health questionnaire for parents was also performed. An evaluation was carried out at the time of recruitment and 1 year later to explore the effectiveness of the comprehensive oral health care model. Results: The differences in decayed teeth (dt), decayed tooth surfaces (ds), filled teeth (ft), filled tooth surfaces (fs) and the ratio of ft /(dt + ft) between the two groups were statistically significant (P 0.001) at 1 year. The incidence of caries in the control group was higher than that of the test group (P = 0.02). The rate of awareness of oral health knowledge (P = 0.01) and the practice of good diet habits (P = 0.02) by parents in the test group were significantly higher than those in the control group. Conclusion: The present study demonstrated that the comprehensive oral health care program reduces and prevents caries amongst children with s-ECC. Keywords: caries, child, comprehensive oral health care