Objective To recognize the status of dental caries and filling treatment of deciduous teeth among Hui and Han preschool children in Ningxia. Methods Making oral health examination for 2 592 Hui and Han preschool children aged 3 to 5 years old in six counties (cities,districts) of Ningxia.The common caries indexes of deciduous teeth were classified statistical by the local GDP level,urban and rural,age,gender,ethnic and so on. Results 1)The prevalence of dental caries and the mean dmft score were 57.41% and 2.51.According to GDP from high to low between the three regions,the prevalence of dental caries had no significant difference,while the mean dmft of Guyuan city were lower than those of Yinchuan and Wuzhong,the difference was statistically significant (t=2.239 and 3.457,P<0.05).2)Along with the growth of the age,the prevalence of dental caries increased gradually,the mean dmft with significant difference between the three years old and four years old(t=-2.837,P<0.05), but no significant difference between the four years old and five years old(t=-1.700,P>0.05).3)Hui and Han preschool children had no significant differences in the prevalence of dental caries and the mean dmft (χ²=2.045,t=1.508,P>0.05).4)The filling rate is relatively low,but the urban was higher than the rural,the difference was statistically significant (χ²=86.016,P<0.05). Conclusions Dental caries of deciduous teeth among preschool children is early in Ningxia,the filling rate was very low,there are no significant different in Hui and Han,so oral health education and preventive intervention should be strengthened.