Abstract: ObjectiveTo understand the timely vaccination of National Immunization Program(NIP)in floating children in Wenzhou and to analyze the factors that affect timely vaccination rate for taking effective measures.MethodsStratified sampling was used to investigate the demographic features of 1301 floating children and their guardians in 15 towns of 3 counties in Wenzhou,including their NIP vaccination,the guardians'knowledge of vaccination,attitude,service and utilization of vaccination,and to analyze the factors affecting NIP timely vaccination rate among the floating children.ResultsFor the children>1 year old,the vaccination rate of seven NIP vaccines(BCG,OPV,DTP,MV,HepB,JEV,and MPV) was 58.4%,44.0%,44.7%,60.5%,47.6%,45.0%,and 25.1%,respectively.The timely vaccination of 5 of 7 vaccines was 16.1%.For the children>2 years old,the timely vaccinations of OPV,DTP,MV and JEV booster immunization was 45.7%,42.5%,20.2%,and 7.4%,respectively.Unconditioned logistic regression showed that the major factors affecting the timely vaccination rate of 5 vaccines were the birth place and the number of child in the family.ConclusionThe timely vaccination rate of NIP vaccines in floating children is relatively low in Wenzhou.Thus the awareness of their parents and the service of NIP should be strengthened.