Objective To evaluate the efficacy of transversus abdominis plane block (TAPB) with different doses of dexmedetomidine mixed with ropivacaine in the pediatric patients undergoing laparoscopic surgery with general anesthesia. Methods Eighty patients of both sexes, aged 3-6 yr, weighing 10-30 kg, scheduled for elective single-channel laparoscopic appendectomy, were divided into 4 groups (n=20 each) using a random number table method: 0.5 μg/kg dexmedetomidine plus ropivacaine group (group DR1), 1.0 μg/kg dexmedetomidine plus ropivacaine group (group DR2), 1.5 μg/kg dexmedetomidine plus ropivacaine group (group DR3), and ropivacaine group (R group). Bilateral TAPB was performed under ultrasound guidance after the end of anesthesia induction.In group TR, 0.25% ropivacaine 0.5 ml/kg was injected, the 0.5 ml/kg mixture of 0.5, 1.0 and 1.5 μg/kg dexmedetomidine and ropivacaine at a final concentration of 0.25% was injected in DR1, DR2 and DR3 groups.Anesthesia was maintained by intravenously infusing remifentanil and inhaling sevoflurane.Cisatracurium was intermittently injected to maintain muscle relaxation.Ibuprofen was taken orally to maintain postoperative FLACC score <4.The intraoperative consumption of remifentanil, tracheal extubation time, duration of anesthetic recovery room stay, requirement for ibuprofen, and occurrence of opioids- and TAPB-related complications were recorded. Results There was no significant difference in the intraoperative consumption of remifentanil or tracheal extubation time between four groups (P>0.05). Compared with group R, the requirement for ibuprofen was significantly decreased in DR2 and DR3 groups, the duration of anesthetic recovery room stay was significantly prolonged in group DR3 (P 0.05). Compared with group DR1, the duration of anesthetic recovery room stay was significantly prolonged, and the requirement for ibuprofen was decreased in group DR3, and the requirement for ibuprofen was significantly decreased (P 0.05). Compared with group DR2, the duration of anesthetic recovery room stay was significantly prolonged (P 0.05). No patients developed opioids- or TAPB-related complications. Conclusion TAPB with 1.0 μg/kg dexmedetomidine mixed with ropivacaine provides good efficacy for the pediatric patients undergoing laparoscopic surgery with general anesthesia. Key words: Abdominal muscles; Nerve block; Dexmedetomidine; Amide; Child; Anesthesia, general; Laparoscopy