Abstract: Objective To investigate two-week prevalences and influential factors of cold and diarrhea among rural children aged under 3 years in 4 provinces in central-west China.Methods Totally 1 272 children under 3 years old were selected from 16 counties in Xinjiang,Shanxi,Gansu,and Qinghai province with multi-stage stratified randomization method and investigated on two-week prevalence rates of cold and diarrhea.SPSS 19.0 software was used to carry on statistical analysis.Results The two-week prevalence rates of cold and diarrhea for the children was 26.8%and 19.9%,respectively.The prevalence rate of diarrhea of the minority and Han children was 25.0% and 12.5%.The prevalence rate of diarrhea in minority children was higher than in Han children(χ²=30.146,P=0.000).The two-week prevalence rate of cold was different among the children with mothers of different education level(χ²=37.627,P=0.000)and so as the two-prevalence rate of diarrhea (χ²=57.914,P=0.000).The two-week prevalence rate of diarrhea was different among the children with the mothers of different age(χ²=6.873,P=0.009).Multiple regression analyses showed that with the mother of high education level(odds ratioOR=0.634)was a protective factor for avoiding cold.Compared with that in Qinghai,the two-week prevalence rates of cold and diarrhea for the children in Xinjiang(OR=2.183)and Gansu(OR=1.943)were higher.With mothers of high education(OR=0.517)and younger age(OR=1.910)were protective factors for the children to avoid diarrhea.Compared with that in Qinghai,the two-week prevalence rate of diarrhea for children in Xinjiang(OR=2.379)was higher.Conclusion Health education on disease prevention among the mothers and caregivers is a major strategy to reduce the prevalence rates of cold and diarrhea in rural children under 3 years old in western China.