OBJECTIVE To investigate the treatment plan for az treonam-resistant metallo- β-lactamase（MBL）-producing Enterobacteriaceae infection in pediatric solid organ transplant recipients. METHODS The clinical data of aztreonam-resistant MBL-producing Klebsiella pneumoniae caused intra-abdominal infection of an infant after liver transplantation were retrospectively analyzed. Abdominal infection occurred after operation. The pathogenic bacterium was MBL-producing K. pneumoniae . The drug sensitivity results showed that the infant was resistant to aztreonam. Based on the results of sensitivity test ，polymyxin B combined with tigecycline were selected as initial regimen. The treatment effect was poor ，with recurrent disease and shock spots. The clinical pharmacist assisted the clinician to formulate treatment regimen of ceftazidime avibactam 0.5 g，q8 h combined with aztreonam 0.18 g，q6 h. Relevant domestic and foreign literature were reviewed ，and the treatment plan of MBL-producing Enterobacteriaceae infection after solid organ transplantation was summarized. RESULTS & CONCLUSIONS The infant was finally cured and discharged with ceftazidime avibatan combined and aztreonam. Several foreign literature reported that ceftazidime avibactam combined with aztreonam could effectively treat the infection caused by aztreonam-resistant MBL-producing Enterobacteriaceae infection in patients with organ transplantation. It is expected to be an effective treatment for aztreonam-resistant MBL-producing Enterobacteriaceae infection in pediatric solid organ transplant recipients.