Objective To investigate the efficacy and safety of the postoperative analgesia after thoracotomy with different patient-controlled intravenous analgesia (PCIA)medication.Methods One hundred and twenty ASA Ⅰ or Ⅱ patients scheduled for elective thoracic surgery were randomly di-vided into four groups according to different PCIA formula:group S received sufentanil 3 μg/kg;group SD received sufentanil 1.5 μg/kg plus dezocine 0.3 mg/kg;group SF received sufentanil 1.5μg/kg plus flurbiprofen axetil 3 mg/kg;group DF received dezocine 0.3 mg/kg plus flurbiprofen ax-etil 3 mg/kg.For all four goups,the applied medicine was diluted with 0.9% saline to 300 ml,and was infused at 5 ml/h with a bolus dose of 3 ml.The lockout time was set at 1 5 min.The VAS and Ramsay sedation scale were recorded 2,4,8,24,48 h after surgery,respectively.Total pressing times and the side effects were also recorded for the 24 h period after the surgery.Results There were no significant differences of the VAS score at the time 2,4,8,24 and 48 h post surgery of press num-bers within 24 h postoperatively among all groups.The Ramsay sedation scale was significantly high-er at the time 2,4,8,24 h after surgery in group S than those in other three groups (P <0.05).The side effects were more in group S than those in other three groups (P <0.05).Conclusion Compared with sufentanil alone,combination therapy is safer and more effective for analgesia after thoracic sur-gery.With good outcomes and less side effects,it deserves more consideration in clinics.