Abstract: Objective To compare the clinical safety and efficacy of fentanyl and remifentanil in thoracic surgery,and provide reference for reasonable anesthesia choice in thoracic surgery. Methods Total 142 patients undergoing thoracic surgery in our hospital from February 2014 to February 2015 were chosen for the study and were randomly divided into two groups according to the anesthesia methods,the Fentanyl group with 70 cases(group A) and the Remifentanil group with 72 cases of patients(group B).The anesthetics in group A was propofol combined with fentanyl[25 ng/(kg·min)],and the anesthetics in group B was propofol and remifentanil[0.2 μg/(kg·min)].The main physiological indicators during surgery and postoperative recovery time were compared.The restlessness 15 min after the removal of catheter was assessed with Riker sedation-agitation score (SAS),as well as the pain postoperative 1,6,12 h using visual analog pain score(VAS),and the pain scores and the sedation-agitation score were compared. Results There was no significant difference in the mean blood pressure,oxygen saturation and respiratory rate between the two groups,and the mean heart rate group B was(60.2±7.8),and group A was(77.6±5.9),and the recovery time of the group B was (9.1±1.8)min,and group A was (15.0±6.1)min,P＜0.05,and the difference was statistically significant.The sedation-agitation score of group B was(2.1±0.9),and group A was(3.4±0.8),P＜0.05.The pain scores of group B postoperative 1,6,12 h were both lower than that of group A,P＜0.05,and the difference was statistically significant. Conclusion In the thoracic surgery,compared with fentanyl,the anesthesia time of remifentanil was shorter than that of the Fentanyl,and remifentanil had better analgesic and sedative effects,and was a safety,efficacy and ideal narcotic analgesic drugs,worthy for clinical application.