Abstract: Objective The present study was conducted to gain insight into the quality of surveillance on acute flaccid paralysis and provide information for the maintenance of the polio-free. Methods Analysis was made on the epidemiological characteristics of the acute flaccid paralysis (AFP) cases and the quality of the surveillance system in the City of Baoji from 1996 to 2005. Results A total of 162 cases of AFP was reported in the 10 years with 53.1% of them being children under 5 years of age. Every month in the 10 years could see new AFP cases. Polio viruses (PV), which were vaccine strains, were isolated in 3 of the 143 AFP specimens with one case (PV I + III type) diagnosed as vaccine-associated paralytic poliomyelitis. Poliomyelitis was rule out in the remaining. The annual average incidence of non-polio AFP among children under 15 years of age was 1.5/lakh. The rate of investigation within 48 hours was 96.3 %, with the rate of satisfactory sampling, the rate of stool samples being sent to the polio lab of the provincial CDC within 7days, the rate of timely follow-ups, the timeliness rate of zero case reporting and the timeliness rate of active surveillance being 96.3%, 84.6%, 85.3%, 80.9%, 84.7%, and 92.0%, respectively. Conclusion The indice of AFP surveillance system from 1996 to 2005 are being improved gradually, and have been reached and kept poliomyelitis free. Active surveillance is the key to further improvement of the quality of AFP surveillanec.