Abstract: ObjectiveTo investigate the mechanism of pathogens.resistance to aminoglycosides in paediatrics.infectious diseases in Jilin regions and guide the rational use of antibiotics.Methods242 cases of specimens from the respiratory tract were collected,and the bacteria were iso lated and identified from April in 2005 to May in 2006.The drug susceptibility were tested,the aminoglycosides modifying enzymes were detected by PCRtechnique and the PCR conducts were cloned and sequenced.Results366 strains of bacteria were isolated from 242 specimens including 172 strains of G^- bacillus accounting for 40 percent of K.pneumoniae and 28.8 percent of E.coli.The most frequent resistance to streptomycin were over 50%,the resistance to gentamycin,kanamycin,amikacin,netimycin was over 35% and the resistance to etimycin and dibamycin was lower 15%.The bacteria which were resistant to streptomy cin and gentamycin carried the ANT(3″)and AAC(3')gene respectively.ConclusionThe bacteria from the respiratory tracthave the highest resistant rates to streptomycin and the lowest resistant rates to etimycin and dibamycin,which harboured the same type of aminoglycosides modifying enzymes genes used in treating diseases.