Objective: This in vitro study aimed to investigate the remineralization effect of the natural medicine epigallocatechin gallate on artificial enamel caries in primary human teeth. Methods : We divided 30 sound primary upper anterior teeth into 3 groups according to a random number table, including experimental group (epigallocatechin gallate group), positive control group (NaF group) and blank control group (artificial saliva group), with 10 teeth in each group. After test in vitro, Micro Hardness Tester was applied to measure hardness of samples before and after demineralization. Scanning electron microscopy (SEM) was used to observe the result of primary enamel surface remineralization. Results: A significant increase in enamel surface microhardness between the three groups after remineralization (F=1 199.975, P < 0.05). The difference between 2 groups was compared with each other among 3 groups. Statistical significance was found (vs experimental group q=41.986, P < 0.05; vs positive control group q=68.174, P < 0.05), suggesting that both positive control group and experimental group could promote the remineralization of primary enamel, and the effect of epigallocatechin gallate was weaker than NaF (q=26.188, P < 0.05 ). The results from SEM indicated that there was large amount of sediment on the surface of primary enamel surface of incisors in the experimental group and positive control group, while primary enamel surface of incisors in the blank control group was honeycomb and uneven, with less sediment. Conclusion Based on this in vitro study, epigallocatechin gallate can promote the remineralization of demineralized enamel of primary teeth, indicating its potential use as a natural remineralization medicine.