Abstract： Objective To investigate the effects of controlled subcutaneous analgesia(PCSA) with sufentanil in patients underwent abdominal surgery and the occurrence of adverse reactions. Methods 90 patients underwent abdominal surgery were randomly divided intothree groups with 30 cases each. Group Ⅰ :sufentanil 0. 04μg · kg-1 ·h-1 for postoperative analgesia; Group Ⅱ : sufentanil 0. 06μg · kg-1 · h-1 for postoperative analgesia; Group Ⅲ :sufentanil 0.08μg/kg · h for postoperative analgesia;PCSA started at the end of operation with catheter buried in deltoid muscle. Visual analgesia scale(VAS) ,Rasmay scale and side effects were recorded at 4,8,16,24 and 48h after operation. Results VAS scores decreased significantly in group Ⅱ and group Ⅲ compared with that in group Ⅰ ( all P ＜ 0.05) ;There were no differences of Ramsay scores between groups ( all P ＞ 0. 05) ;There were three cases of respiratory depression in group Ⅲ. Conclusion PCSA with sufentanil (0.06μg/kg) had exact analgesic effects for postoperative abdominal surgery patients with less adverse reactions.