Abstract: ObjectiveTo study virus infection state in infants and young children suffered with acute respiratory infection in Zhoushan Archipelago.MethodsNaso pharyngeal secretion was obtained from 1217 in patient children diagnosed as acute respiratory infection between April 1st, 2004 and November 30 th,2008,and respiratory syncytial virus(RSV),adeno virus,para influenzavirus Ⅰ,Ⅱ,Ⅲ and influenza virus A,B were detected by direct immunofuo rescence asssay.ResultsOf 1217 samples,360 samples(29.58%)were shown to beviral positive,of which,RSV accounted for 213(17.50%),ADV 69(5,67%),IFV A 35(2.88%),IFV B 17(1.39%),Pig I9(0.74%),PIV Ⅰ 13(1.07%),and PIV Ⅲ4(0.33%)respectively.The virus positive rate was the highest in <3 months group(45.67%),and the positive rate decreased gradually with the increase of children's age.The virus positive rate in winter and spring was smiilar to that of in the summer and autumn.There was a higher virus detection rate in children with bronchiolitis than in those with acute bronch it is,acute bronchial pneumonia and upper respiratory tract infection.ConclusionRSV was the most common pathogens in in fants and young children suffering from acute respiratory infection in Zhoushan Archipelago.The virus infection rates in young childre with asthmatic disease was higher.The diagnosis of viral pathogens should be strengthened to provide a reliable evidence for clinical diagnosis and treatment.