Objective: To evaluate the economic effectiveness of the Harbin school-age Integrated Oral Health Intervention Pro- gram for the prevention of dental caries in first permanent molars, and to provide economic evidence for further expansion of the pro- gram coverage. Methods: A Markov model was established based on the data from the comprehensive oral health intervention pro- gram for school-age children in Harbin. Results: The number of dental caries was 29 909 in the sealing group and 83 533 in the blank group, and the caries prevalence were 8.92% and 24.92%, respectively, and the caries prevalence was reduced by 16.00% in the sealing group. Compared with the blank group, the ICER and ICUR of the sealing group were -33.69 yuan/a caries avoided and -36.88 yuan/QATY, respectively. The cost-effectiveness and cost-utility analysis showed that the sealing group was an absolute superior strategy. Sensitivity analysis showed that the model was stable. Conclusion: Vulcanization of the first permanent molars of school-age children for the prevention of dental caries is extremely economical and further expansion of the programme is recommended.