Abstract: Objective The study was conducted to investigate the poliovirus antibody levels among local residents and floating population after the routine and intensified immunization with oral polio vaccine(OPV) in Ouhai district,Wenzhou city,Zhejiang province,and evaluate the immunization effects,providing evidence for the formulation of immunization strategies in future.Methods Seven age groups(1 years,1 to 2 years,3 to 4 years,5 to 6 years,7 to 14 years,15 to 19 years,and 20 years) with 15 to 20 persons in each selected from local residents and floating population using the stratified random sampling method were surveyed,resulting in a total of 478 participants.Blood samples were collected and tested for the neutralizing antibodies using the neutralization test.Results The neutralizing antibody-positive rates for poliovirus type Ⅰ,Ⅱ,Ⅲ were 97.53%,98.77% and 93.83% respectively among local residents,the geometric mean titers(GMT) being 1∶104.53,1∶131.33,and 1∶37.87.The neutralizing antibody positive rates among floating population were 96.60%,95.74%,88.51%,respectively,the GMT being 1∶120.31,1∶110.12,and 1∶31.25.Conclusion An effective immune barrier has been established after the implementation of routine and intensified OPV immunization in Ouhai district,Wenzhou city.However,the immunity levels of floating population were lower than the immunity levels of local residents.Therefore,the improvement of the immune planning and management for floating children will contribute to the prevention of polio.