Objective:To evaluate the effect of esketamine combined with ultrasound-guided dorsal penile nerve block (DPNB) on negative postoperative behavioral changes (NPOBCs) in pediatric patients undergoing circumcision under general anesthesia.Methods:One-hundred and ninety-five pediatric patients, aged 4-8 yr, with body mass index of 10-35 kg, of American Society of Anesthesiologists Physical Status classificationⅠ or Ⅱ, undergoing elective circumcision under general anesthesia, were selected and divided into 3 groups ( n=65 each) using a random number table method: esketamine group (group E), DPNB group (group D) and esketamine combined with DPNB group (group ED). Propofol 1.5 mg/kg was intravenously injected, and the patients were admitted to the operating room after consciousness disappeared in the 3 groups. Esketamine 0.5 mg/kg was intravenously injected in E and ED groups, and the equal volume of normal saline was given in group D. D and ED groups underwent bilateral DPNB with 0.25 % ropivacaine 0.15 ml/kg under ultrasound guidance, with the maximum total amount of the drug not exceeding 10 ml. Fentanyl 1.0 μg/kg and propofol 2.0 mg/kg were intravenously injected prior to the skin incision in the three groups. If intraoperative body movement occurred, propofol 10 mg was added, which could be repeated. The occurrence of intraoperative body movement, respiratory depression and amount of propofol added was recorded. When postoperative pain (FLACC score >4) occurred, flurbiprofen 1 mg/kg was intravenously injected for analgesia, and the usage of flurbiprofen was recorded. When emergence agitation(PEAD score>10) occurred, propofol 1 mg/kg was intravenously injected for sedation, and the occurrence of emergence agitation was recorded. Parents were followed up by telephone at 1, 7 and 30 days postoperatively to assess the occurrence of NPOBCs using the PHBQ scale. Results:Fifty-six patients in group E and 59 patients in D and ED groups finally completed the study.Compared with group E, the incidence of intraoperative body movement was significantly decreased, the amount of additional propofol was reduced, the emergence agitation score, incidence of emergence agitation and severe agitation and usage rate of postoperative flurbiprofen were decreased, and the incidence of separation anxiety at 7 and 30 days postoperatively was decreased in D and ED groups, and the incidence of intraoperative respiratory depression was significantly decreased, and the incidence of NPOBCs at 7 and 30 days postoperatively was decreased in group ED ( P<0.05). Compared with group D, the incidence of intraoperative respiratory depression was significantly decreased, the amount of additional propofol was decreased, the usage rate of postoperative flurbiprofen and incidence of sleep anxiety at 1 day postoperatively were decreased ( P<0.05), and no significant change was found in the incidence of NPOBCs at each time point after operation in group ED ( P>0.05). Conclusions:Esketamine combined with ultrasound-guided DPNB can reduce the occurrence of NPOBCs in pediatric patients undergoing circumcision under general anesthesia.