Abstract: Objective To investigate the efficacy and the incidence of side effects of Sufentanil and Fentanyl for post-operation patient-controlled subcutaneous analgesia（PCSA）. Methods Databases including MEDLINE, the Cochrane Library, PubMed, EMBASE, CBMDisc, CNKI, VIP, Wanfang data were searched. Randomized controlled trials（RCTs） of sufentanil versus Fentanyl for post-operation PCSA were included. The quality of the trials was critically assessed according to the Cochrane Handbook 5.0. RevMan 5.1 software was used for meta-analysis. Results 5 trials including 293 patients were analyzed. The results of meta-analysis showed that: ① Visual analog scale（VAS）: There were no significant differences at 4 hWMD=-0.11, 95%CI（-0.35, 0.14）, P=0.39, 8 hWMD=-0.11, 95%CI（-0.54,0.31）, P=0.60, 12 hWMD=-0.32, 95%CI（-0.97, 0.33）, P=0.33 and 24 hWMD=-0.24, 95%CI（-0.88, 0.39）, P=0.45 between the two groups. But the VAS at 48 hWMD=-0.49, 95%CI （-0.75, -0.22）, P=0.000 3 was decreased in Sufentanil group. ② Side effects: There were no significant differences in the side effects of nausea, vomiting and dizziness between the two groups RR=0.20, 95%CI（0.02,1.64）, P=0.13; RR=0.33, 95%CI（0.04,3.08）, P=0.33. Conclusion Both Fentanyl and Sufentanil are used for PCSA, but Sufentanil is more suitable for patients in needs of long-term analgesic.