Objective:To investigate the distribution,characterization of class 1 integron and its action in multi-resistance in Pseudomonas aeruginosa. Methods:PCR and DNA sequencing methods were undertaken to clarify the type and context of variable region of class 1 integron;the susceptibility of class 1 integron positive strains to five represented antibiotics was determined by agar dilution method;conjugation experiment was carried out to disclose its transferable property;and lastly,pulsed-field gel electrophoresis pattern was performed to explain the genetic relationship of those class 1 integron positive Pseudomonas aeruginosa. Results:Of 47 isolates,29 strains of Pseudomonas aeruginosa were found containing class 1 integron,and no class 3 integron was detected. A length of 4.300 bp variable region was found in all the class 1 integron positive strains by PCR amplification. The resulting DNA sequences revealed that it was comprised of a new array of aac(6’)-Ⅱ-aadA13-cmlA8-oxa-10 gene cassettes,and the genbank number is EU182575. According to the database in genbank,aadA13 was previously unreported in Pseudomonas aeruginonsa; chloramphenicol efflux pumping determinant,named as cmlA8 shares 95% nucleotide similarity to cmlA5 gene. All those class 1 integron positive isolates showed high homology by PFGE pattern analysis after digestion with SpeⅠ. Conclusion:Class 1 integrons disseminated among correlated Pseudomonas aeruginosa in our hospital possessing novel gene cassettes and mediated the resistance and multi-drug resistance.