Objective：To evaluate the effect of different analgesia methods on chronic postoperative pain after cesarean section. Methods：150 monomorphic primiparas scheduled for elective cesarean section under epidural anesthesia were enrolled and randomly assigned to receive 10 mg/ml tramadol through patient controlled intravenous analgesia（group PCIA，n=50），receive 1.5 mg/ml ropiva－caine plus 5 mg/ml tramadol through patient controlled epidural analgesia（group PCEA，n=50） and receive 100 mg tramadol by muscle injection per 12 hours （group MI，n=50）. Postoperative analgesia lasted 48 hours in each group. VAS scores，tramadol con－sumption，the events of requiring rescue analgesia as well as side effects such as nausea and vomiting during the first 48 hours follow－ing surgery were recorded. The incidence of chronic pain was observed at the third and sixth months after operation. Results：In the first 24 hours after operation，VAS score in group PCEA was significantly lower than in other groups，and group PCIA had lower VAS score than group MI. In the second 24 hours，VAS scores were equivalent among the 3 groups.The consumption of tramadol during analgesia period was the lowest in group MI and highest in group PCIA. The rate of requiring rescue analgesia was the lowest in group PCEA whereas highest in group MI. The occurrences of nausea and vomiting were similar in group MI and group PCIA，which were significantly higher than in group PCEA. The incidence rate of pain after operation was significantly lower in group PCEA than in other groups in the third and sixth months，and lower in group PCIA than in group MI at the same time. The pain intensity was lower in group PCEA than in group PCIA as well as group MI three months after operation. Conclusion：PCEA is a good alternative in pre－venting the development of chronic pain after cesarean section.