The aim of this study was to investigate virulence and drug resistant mechanism of multidrug resistant Pseudomonas aeruginosa (PA) isolated from water sample of fishery pond, in order to provide scientific support for practical aquaculture disease treatment, effective management of aquaculture environment and aquatic food safety control. Antimicrobial susceptibility of PA isolates under this study were examined by using standard Kirby Bauer disk diffusion method according to the Clinical and Laboratory Standards Institute (USA, 2010 Edition), showing distinct susceptibility to nine antimicrobial agents belonging to six drug classes tested. All PA isolates were resistant to trimethoprim and rifampin, of which, 90% were to ampicilin and kanamycin, and 10% were to gentamycin. The genes involved in pathogenicity，intrinsic and transferred antibiotic resistance were detected by polymerase chain reaction (PCR). The toxA and exoU genes were absent from the PA isolates tested, 50% of which were exoS⁺/exoU^- infectious genetype, and none of which were exoS^-/exoU⁺ cell toxic genetype that usually existed in clinical PA isolates. Subsequent analysis revealed that the multidrug efflux pumps including MexAB-OprM, MexXY-OprM and MexVW-OprM were present in all PA isolates, 20% of which were positive for ampC gene, whereas the other four efflux pumps including MexEF-OprN, MexJK-OprM, MexCD-OprJ and MexGHI-OpmD were fully or partially deficient. In addition, the comINT gene of class Ⅰ-Ⅲ integrons was negative in the PA isolates, however, the functional genes（int，soj，pilS2，pilD）of conserved module structures of integrative conjugative elements (ICEs) were detected positive, suggesting possible transfer activity of the ICEs detected in the PA isolates. This study revealed the major mechanism under multidrug resistance of the PA isolates mediated by efflux pumps encoded by chromosome genes, and constituted the first evidence for mobile genetic element ICEs in PA isolates of environmental origin.