Abstract: Objective To examine the stauts of childhood category B vaccination and its related factors in China.Methods Totally 2 160 households with children of 1-3 years old in the provinces of eastern, central and western part of China(Jiangsu, Hubei, and Gansu)were sampled with random cluster sampling.Logistic regression was used in data analysis.Results There were 49.61% of the children having at least one self-paid vaccination.Compared with the low income group, the second low income group(odds ratio OR=1.750, 95% confidence interval95% CI=1.182-2.590), the moderate income group(OR=2.184, 95%CI=1.430-3.335), the second high income group(OR=1.527, 95%CI=0.968-2.409)had a high probability to have self-paid vaccination.The children from Hubei(OR=39.231, 95%CI=27.201-56.584)and Jiangsu province(OR=10.872, 95%CI=7.662-15.428)were more likely to be vaccinated with self-paid vaccine than those from Gansu province.Compared with the children from rural area, urban children were more likely to be vaccinated with self-paid vaccine(OR=2.294, 95%CI=1.602-3.284).We found a correlation between parent physician examination and the status of their children's self-paid vaccination(OR=1.375, 95%CI=1.066-1.773).Conclusion Disparities in self-paid vaccination across regions were observed.Economic cost is an important barrier for accessibility of self-paid vaccination in China.