Abstract: Objective To compare the effects,drug dosage and side effects of three modes of postoperative epidural analgesia in breast cancer patients,so as to choose the better one. Methods 60 postoperative breast cancer patients were randomly divided into three groups (n=20).The ingredients of the drug in three groups are same.Group Ⅰ were infused with the patient-control analgesia mode (PCA),Group Ⅱ used with coninuous,constant mode (CC),Group Ⅲ used continuous,constant mode short-time,together with PCA(CC+PCA).The patient's Bp、HR and SpO2.were monitored constantly and the 24-hour injection dosage was recorded.The analgesia effect、side effects were under observation. Results (1)The 24-hour drug dosages in Group Ⅰ、Ⅱ、Ⅲ were 31.65±12.04ml、48ml、34.60ml±11.25ml.The Group Ⅰ、Ⅲ were obviously higher than Group Ⅱ(P＜0.05).(2)The Group Ⅰ、Ⅲ were superior to Group Ⅱ in 24-hour analgesia effects.(3)During the period of observation,the Bp,HR,and RR were all within normal range.There was no significant difference between the three groups in vomiting occurrences. Conclusion CC+PCA mode is superior to other modes in postoperation epidural analgesia.It not only can meet the needs of individuals,but also let the patients have a good rest without handling the button frequently.