Abstract: Objective To compare effects of different concentrations of sufentanil on patient controlled subcutaneous analgesia（PCSA） after resection of esophageal carcinoma. Methods Ninety patients with esophageal cancer receiving radical surgery were enrolled in this study. Using the random number table， they were divided into 3 groups（Ⅰ-Ⅲ group, n=30） according to the doses of sufentanil (3， 3.5， 4 μg/ml) with PCSA for 2， 24， 48，72 h after the surgery. Postoperative pain degree was evaluated by numerical rating scale（NRS）. The degree of calm on patients receiving opioid analgesic therapy was evaluated by level of sedation（LOS）. The failure rate of patient-controlled analgesia， residual liquid quantity, the total number pressed by the patients with self-control analgesia and the occurrence of adverse reaction(bradycardia， hypotension and itching) were recorded. Results The failure rate of group Ⅰ was 43.3%（13/30）， and that of group Ⅱ and group Ⅲ was about 0. The amount of residual liquid in group Ⅰ was（18.1±0.7） ml， which was less than that in group Ⅱ（33.5±0.2） ml and group Ⅲ（33.2±0.3） ml， and the difference was statistically significant（P<0.05）. The total number of press times in group Ⅰ was 8.1±0.6， which was significantly higher than that in group Ⅱ（1.9±0.5） and group Ⅲ（2.1±0.3）， and the difference was statistically significant（P<0.05）. The scores of NRS in group Ⅰ of 2， 24 and 48 h were higher than those in group Ⅱ and group Ⅲ and the difference was statistically significant（P<0.05）. The score of LOS in group Ⅰ of 2， 24， 48 and 72 h was lower than those in group Ⅱ and group Ⅲ and the difference was statistically significant（P<0.05）. The incidences of itching， hypotension and bradycardia in group Ⅲ were higher than those in group Ⅰ and Ⅱ（P<0.05）. Conclusion The appropriate concentration of sufentanil on postoperative patients of esophageal cancer radical surgery with patient controlled subcutaneous analgesia is 3.5 μg/ml.