In this study, identification and pathogenicity of six strains Aeromonas hydrophila sensitivite to tetracyclines and fluoroquinolones, with sub-inhibitory concentration subculture method, artificial induction of resistant to tetracycline, doxycycline, norfloxacin and levofloxacin resistance A. hydrophila were obtained. The differences about the major protective antigen lipopolysaccharide and outer membrane protein of outer membrane of sensitivite and resistant A. hydrophila were compared. Channel catfish(Ic...