Objective To understand the molecular evolutional characteristics of hemagglutinin(HA)gene of influenza A(H3N2)virus in Quzhou,Zhejiang province,from 2015 to 2017 and provide scientific evidence for the prevention and control of influenza.Methods A total of 18 influenza A(H3N2)virus strains isolated in Quzhou from 2015 to 2017 were selected. The full-length of HA genes were amplified by RT-PCR and sequenced. Bioinformatics software was used to analyze the sequences.Results The homologies of nucleotide and a...