Abstract: Objective To compare the efficacy and safety of cryoanalgesia and patient-controlled epidural analgesia (PCEA) after thoracotomy. Methods Forty patients undergoing elective thoracotomy were randomly divided into cryoanalgesia group (L group, n=20) and PCEA group (n=20). Before chest closure, 4 costal nerve branches (at, above and below the incision, and one for inserting drainage tube) were isolated and frozen for 90 s at -40 to -89 ℃ in L group. The mixture of 0.2% ropivacaine and 3 mg morphine solved in 100 ml normal saline was administered in patients of PCEA group through epidural catheter with PCA pump. The visual analogue scale scores for the analgesic effect and the incidence rate of complications were investigated at different time points every other two days after surgery. Results There was no difference in the analgesic effects between the two groups, but the rates of ST-T changes, arrhythmia and hypertension as well as the incidence rate of the complications such as postoperative nausea and vomiting, itch and respiratory depression etc differed significantly. Conclusion Given the respective advantages and disadvantages of cryoanlgesia and PCEA, both of which prove to be effective for pain management postthoracotomy, their choice must be decided according to clinical needs.