〔Abstract〕 Objective To explore the preventive effect of epigallocatechin gallate(EGCG) on dental caries through the rat dental caries model, and provide experimental and theoretical basis for clinical research of natural medicine EGCG on preventing caries. Methods Twenty-four SD rats were selected and randomly divided into EGCG group, sodium fluoride(NaF) group, chlorhexidine acetate(CHX) group and distilled water(control) group, each with 6 rats. The rats were inoculated with standard strain ofstreptococcus mutans(S.mutans) and given cariogenic feed 2000# and 5% sucrose solution. The oral cavity of rats was rinsed and coated with minimum inhibitory concentration(MIC) EGCG, 250 mg/L NaF solution, 0.12% CHX solution and distilled water, respectively. After 6 weeks of continuous treatment, the rats were sacrificed. The jaws of the rats were collected and analyzed by Keyes score method to evaluate the caries of the rats′ maxillary molars. Results The Keyes scores of caries showed that compared with the control group, drugs in each group had different degrees of inhibition effect on the formation and severity of caries in rats. Among them, the EGCG group had better effect on enamel caries(P<0.01) and dentin caries, and had much better effect on dentin deep caries(P<0.001) of maxillary fossa and fissure caries in rats. However, the prevention and treatment effect of superficial and middle dental caries was lower than that of CHX group. Conclusion EGCG with MIC concentration reduces the incidence and severity of dental caries, and has a significant inhibitory effect on the occurrence of dental caries in rats.