Objective To survey implementation of national expanded immunization program in children under 5 years old in Shandong province,and analyse its influencing factors,then to provide scientific basis for formulating strategies and policies of health literacy. Methods A sample of 1 502 children under five years old in the 17 cities of Shandong province in 2013 was included in this study through stratified cluster sampling.The basic demographic characteristics and the vaccination status of the children were investigated and influencing factors were analyzed by multivariate Logistic regression analysis. Results The coverage rate of children under 5 years old was over 90%.The urban and rural coverage rate of category B vaccines were 71.1% and 83.7% (χ²=34.152,P＜0.05) respectively.The coverage rates of rural children were higher than the urban children of category B vaccines except varicella vaccine.The results of multivariate regression analysis demonstrated that age,urban,census and annual household income were considered as the influencing factors. Conclusions The coverage rate of children under 5 years old in Shandong province is higher,whereas the overage rate of category B vaccine is rather lower,urban and rural shows heterogeneity.Vaccination services provided by medical institutions are expected to be improved.