OBJECTIVE： To evaluate the effects of dezocine on postoperative pain and the levels of inflammatory factor in breast cancer patients. METHODS： 100 breast cancer surgery patients were selected and randomly divided into control group and observation group with 50 cases in each group. All patients received tracheal total intravenous anesthesia intubation， sufentanil 0.3 μg/kg， ivgtt， for anesthesia induction. Control group were infused with sufentanil 10 μg 20 min before the end of surgery. Observation group was given dezocine 2.5 mg intravenously 20 min before the end of surgery. The visual analogue scale （VAS） were recorded in 2 groups 1， 8， 12， 24， 48 h after operation； the levels of CRP， IL-6 and TNF-α were recorded before surgery and 1， 2， 3， 5 d after surgery. The occurrence of ADR was observed in 2 groups. RESULTS： The VAS scores of observation group were significantly lower than that of control group 8， 12， 24， 48 h after surgery， with statistical significance （P＜0.05）. The levels of CRP， IL-6 and TNF-α in 2 groups increased significantly 1 d after surgery， and the control group was significantly higher than the observation group， with statistical significance （P＜0.05）. There was no statistical significance in the levels of CRP， IL-6 and TNF-α in 2 groups between 3 and 5 d after surgery and before operation （P＞0.05）. The incidence of nausea， vomiting， urinary retention， pruritus in observation group was significantly lower than control group， whereas the incidence of anesthesia delay was higher than control group， with statistical significance （P＜0.05）. CONCLUSIONS： Dezocine in better than fentanyl to effectively relieve postoperative pain in patients with breast cancer and reduce postoperative inflammation， and result in mild gastrointestinal reactions and good tolerance； but the patients are prone to anesthesia delay， intensive care should be strengthened.