Objective To analyze the age difference of gram negative isolates(GNB)from blood culture and antibiotic resistance profile between children and adults. Methods Age difference of pathogen distribution of GNB isolated from blood culture during 2015-2017 were retrospectively analyzed. WHONET 5.6 and Graphpad Prism 6 were used to perform Chi-square test on the pathogen proportion and antibiotic resistance rate. Results A total of 20 145 bacterial strains were isolated in Chongqing from 2015 to 2017. The top three strains of GNB were E. coli(56.7％, 6 688/11 799), K. pneumoniae(19.6％, 2 308/11 799), and P. aeruginosa(4.4％, 522/11 799). The resistant rate of E. coli to carbapenems was less than 1％. The resistant rate of K. pneumoniae to carbapenems was about 5％, while the resistant rate of S. marcescens was approximately 9％, similar to E. cloacae. The overall resistance rates of E. coli from adult patients to most antiobiotic agents were significantly higher than those of children, but the overall resistance rate of K. pneumoniae from children was higher than those of adults. The drug resistance rate of A. baumannii was higher than P. aeruginosa. A. baumannii isolates from adult patients were highly resistant to all drugs tested and more resistant than those from pediatric patients. Conclusions Majority of GNB strains isolated from blood culture were E. coli and K. pneumoniae, for which carbapenems are still active. More attention should be paid to carbapenem-resistant K. pneumoniae from children and A. baumannii from adults. National surveillance of nosocomial bloodstream infection should be highly evaluated.