OBJECTIVE To explore the distribution of related resistance genes of chloramphenicol and tetracycline in Pseudomonas aeruqinosa isolates.METHODS The antibiotics susceptibility was tested by K-B method,catB cmlA,tetA tetB and smr-2 were detected by polymerase chain reaction(PCR),the gene cmlA was sequenced by PCR fluorescence spectrophotometry.RESULTS The drug-resistant rates of 20 strains of P.aeruginosa against 17 kinds of antibiotics ranged from 10.0% to 100.0%,and multidrug resistant strains were found.The gene of cmlA had been detected in 6 strains of 15 resistant P.aeruginosa isolates,but the genes of tetA,tetB and smr had not been detected.The cml was sequenced,and compared with GenBank,the result showed the gene fragment shared 99.0% homology in nucleotides with the GenBank sequences of cmlA7 and cmlA8.CONCLUSIONS Resistance to antibiotics in P.aeruginosa of our hospital is mainly related to cmlA.The resistance to chloramphenicol and tetracycline was not related to tetA,tetB and smr-2.