Abstract: ObjectiveTo know Epidemio logical feature of acute flaccid paralysis(AFP)cases and condition of surveillance system in Liaoning province,to analyze AFP cases and evaluate the status of surveillance system from 1993.MethodsComparative analysis by using of epidemiological method.ResultsWith the increasing of the sensitivity of AFP cases,the reported incidence was above 1/100,000 consecutive 5 years from 1995;The rate of reported AFP cases counties accounted for total counties of whole province raised from 34% in 1993 to 62% in 1999;AFP cases has no obvious distribution of years and high peak of seasons in recent years;The zero-dose vaccination AFP cases decreased by years,and it only accounted for 1.1% in 1999;The adequate collected rate of two stool specimen was above 80% steadily from 1996.ConclusionThe every indicator of quality control of surveillance system met the need of WHO and Minister of Health.But there were some weak regions and link of surveillance system in Liaoning province,more attention should be paid to surveillance of high-risk regions in order to increase the ability of sur veillance system's recognition on imported wild polioviruses.