Abstract: OBJECTIVE To study the adsorption of H9N2 subtype avian influenza virus isolated during different time periods on erythrocytes of different animals and explore the risk of human to be infected with the virus. METHODS In this study, different strains of H9N2 subtype avian influenza virus isolated from different regions in different periods were used to conduct hemagglutination tests on red blood cells of 14 different animals, including chicken, ducks, geese, pigeons, quails, pigs, sheep, horses, human o-type red blood cells, rabbits, BalB/c mice, ICR mice and rats, and the hemagglutination reaction spectra were described so as to observe the biological characteristics of the different viral strains. RESULTS There were differences in the hemagglutination spectra for animal red blood cells among the different H9N2 avian influenza viruses, which had higher hemagglutination titer for poultry, the second highest mean hemagglutination titer for human type O red blood cells. CONCLUSION H9N2 avian influenza virus not only has high pathogenicity to poultry but also has the risk of infection to human.