Objective To investigate the significance of Dezocine combining Fentanyl used for postoperative PCIA in breast cancer patients.Methods One hundred and twenty six patients with ASA Ⅰ-Ⅲ entered the study.All patients were scheduled for breast cancer operation under intravenous analgesia with tube insertion and treated with PCIA after the operation.They were randomly divided into Fentanyl group (n =63) and Dezocine combining Fentanyl group(n =63).VAS,Ramsay,BCS in two groups were compared al 12 h,24 h,48 h after operation.Side effect was also detected.The changes of T cell subset and IL-2 were analyzed in the patients respectively at the first day before operation,at the first day after operation,at the seventh day after operation.Results At every time point,VAS in research group was significantly lower than that in control group(P ＜ 0.05).However,Ramsay in research group was obviously higher than that in control group(P ＜0,05).There were no significant differences in BCS between two groups (P ＞ 0.05).And no difference was found in the incidence of side effect between two groups (P ＞ 0.05).Compared with control group,the changes of T cell subset,IL-2 had no significant differences in research group at the first day after operation and at the first day before operation (P ＞ 0.05).At the seventh day after operation,the levels of CD4 +,CD4 +/CD8 +,IL-2 in research group were obviously higher than those in control group (P ＜ 0.05).However,the percentage of CD8 + T cells in research group was significantly lower than that in control group (P ＜ 0.05).Conclusions Dezocine combining Fentanyl in PCIA can increase analgesia effect with less side effect.It is positive to improve immunologic function for breast carcinoma patients after operation.