Abstract: Objective Consultation rates of in fluenza-like illness(ILI%)in anoutpatient setting have been regarded as a good indicator of in fluenzavirus activity in community.In this study,we detected the etiology spectrum of the crowd with ILI to evaluate the efficiency of ILI%.Methods 118 ILI patients' nasopharyngeal swabspecimens were collected in Shenyang between Jan.2007 and Apr.2007.All of the specmiens were inoculated into MDCK cells for influenza virusisolation and analyzed for 13 pathogens(influenza A,B and C virus,syncytial virus,para influenza virus,human coronavirus,enteroviru,srhinovirus,human metapneum ovirus,reovirus,adenovirus,Mycoplasma pneumoniae,and Chlamydia pneumoniae) that could cause ILI symptom by multiplex nested RT-PCR assays.Each virus' positive and composing ratio was also calculated.The surve illance data of ILI% were also obtained at the same time.Results The ILI% among the outpatients from Jan.2007 to Apr.2007 was 5.0% on average.PCR positive rate of influenza virus was varied consistently from the peak in January 2007(52.6%,10/19)to 40.0%(8/20)in February,22.8%(10/44)in March and 5.7%(2/35)in April; While rhinovirus,adeno virus,para influenza virus and Chlamydia pneumoniae to gether accounted for more than 30% of positive on average in the period.Conclusion Our data sugge sted that it was very difficult to ascertain whether the patient was really infected by in fluenza virus or other respiratory pathogens that could induce smiilar clinical symptoms,so the influenza surveillance should be carried out effectively by a systemic pathogenic test as well as sensitive clinical definition.