Abstract: Objective To investigate the timely vaccination of Measles Vaccine in floating children in 8 month~4 years old Children in Wenzhou and to analyze the factors that affect timely vaccination rate for effective measures. Methods Stratified sampling was used to investigate the demographic features of 1301 floating children and their guardians in Wenzhou,including the guardians' knowledge of vaccination,attitude,service and utilization of vaccination,and to analyze the factors affecting timely vaccination rate of measles vaccine among the floating children. Results Coverage rate and the timely inoculation rate of measles vaccine were 97.3% and 69.2% respectively. Logistic regression showed that major influence factors associated with coverage included parents' working hours, parity, access of vaccination information, knowledge about whether vaccination was necessary for children, having immunization card or vaccination certificate and so on.Conclusion The timely vaccination rate of measles vaccine in floating children is relatively low in Wenzhou, and therefore the awareness of their parents and the service of national immunization program should be strengthened.Effective intervention should be implemented to improve the timely inoculation rate of measles vaccine.