ABSTRACT
To better understand the molecular characterization ,pathogenesis ,origin ,and evolutionary relationship of the first human-infecting H6N1 influenza virus ,the dataset was downloaded from the Flu and GISAID databases ,and the phy-logenetic trees were reconstructed by maximum likelihood (ML) ,maximum parsimony (MP) and Bayesian inference (BI) . Furthermore ,the evolution rate ,the most recent common ancestor (TMRCA) ,variable sites ,glycosylation sites ,cleavage sites and other some molecular features were also analyzed by bioinformatic means .The results indicated that the HA gene fell into an individual clade with other three H6N1 virus strains isolated from chicken .TMRCA was in 2002 ,and the cluster had a higher evolution rate .The molecular features revealed the HA protein had 5 N-glycosylation sites ,2 O-glycosylation sites and 2 unique variable sites .The cleavage sites had only one basic amino acid and suggested that the human-infecting H6N1 virus strain was low pathogenic .However ,because of the higher substitution rate and viral reassortment ,people should pay more attention .