Abstract: Objective: To observe the effect of ropivacaine combined with tramadol in postoperative extradural analgesia(PCEA).Methods: Fifty patients having undergone operation under extradural anesthesia received extradural cut-over analgesic pump after the operation.The formula of analgesic pump was 0.894% ropivacaine mesylate,0.8 g tramadol and 3-5 mg droperidol,which were diluted to 100 ml with normal saline.The pain score,vital signs and complication were observed at 9,12,24 and 36 hour individually.Results: No pain occurred in forty-nine patients;one patient felt satisfied.Thirty patients had phenomena of hypersomnia.No nausea,vomiting,cutaneous pruritus or respiratory repression was observed.Vital signs were steady.Conclusions: The combined therapy of ropivacaine and tramadol is effective and safe for postoperative analgesia,and has little side effect.