Objective:To investigate the biological characteristics of monoclonal antibodies against avian influenza virus (AIV).Methods:Monoclonal antibodies (mAbs) against AIV H5N1 were prepared and it′s characteristics were identified including subtype,titer,hemagglutination inhibition activity and cross-reactivity with other influenza viruses.Besides,Western blot and immuno-histochemical staining methods were conducted to test the combination of antibodies and antigen ( H5N1 ) and human normal tissues.Results:Immunohistochemical analysis showed that 2 mAbs (H5-32 and H5-35) cross-reacted with human tissues kidney and pancreas respectively.Conclusion:These data indicated that there have some association between the AIV H 5N1 with human tissues, which may provide reference for the study on avian influenza virus infection and pathogenicity .