AIM:To discuss the effect of Chinese nutgall on inorganic materials in the process of enamel caries forming.METHODS:500 g/L Chinese nutgall soaked liquid was used as experimental medicine.380 g/L Ag(NH_3)_2F and 20 g/L NaF were used as positive controls,while the deionised water as negative control.The functions of the above four groups were compared with each other,according to the content of Ca、P and the general demineralization in the demineral solution.RESULTS:According to the inhibition effects on the content of Ca、P and the general demineralization,the four groups from great to little differently were 380 g/L Ag(NH_3)_2F、 20 g/L NaF、 500 g/L Chinese nutgall soaked liquid and deionised water.There were significant difference ( P <0.01) between 500 g/L Chinese nutgall soaked liquid and 380 g/L Ag(NH_3)_2F、500 g/L Chinese nutgall soak liquid and deionised water.While there were significant difference on the content of Ca、P ( P <0.05) and no difference on the general demineralization ( P >0.05) between 500 g/L Chinese nutgall soaked liquid and 20 g/L NaF.CONCLUSION:The results proved that the Chinese nutgall could restrained dissolving of Ca、P and general demineralization. But its inhibition effect on the content of Ca、P was inferior to 20 g/L NaF.Which inhibition effect on the general demineralization was almost equal to 20 g/L NaF its.On this aspect,the 380 g/L Ag (NH_3)_2F has the best effect among the four groups.