OBJECTIVETo understand the timely coverage of 5 kinds of EPI vaccine in Dinghai District, including hepatitis B vaccine (HepB), bacillus calmette guerin vaccine (BCG), oral poliomyelitis attenuated live vaccine (OPV), diphtheria-pertussis-tetanus combined vaccine (DPT), measles attenuated live vaccine (MV), and to analyze the influence factors so as to formulate measures to improve the coverage.METHODSAnalyzing the immunization data and related information of 4258 resident children and 394 floating population born during 2005-2007.RESULTSTimely coverage rate of BCG, HepB, OPV, DPT, MV were 22.26%, 95.020, 90.82%, 91.40%, 95.40% respectively and 48.73%, 74.37%, 76.40%, 80.46%, 84.52%, for floating population. Except for the timely BCG coverage rate was low for resident and floating populations, the timely vaccination rates for other 4 kinds of NIP vaccines in the resident were significantly higher than those in the floating population. The logistic regression analysis showed that inappropriate timing of vaccination, long time waiting for inoculation, lacking of time for the families, long distance from the vaccination sites were four factors that affected the timely immunization of NIP vaccines.CONCLUSIONImplementing the strategy of midwife being responsible for BCG and HepB vaccination can improve the timely coverage of the first dose HepB and BCG: Shorten running inteval of vaccination and available service from the supplier, improve immunization awareness and initiative of the recipients (especially for the floating children's parent/guardian) will be useful to increase the timely NIP vaccine coverage rates.