Abstract: Objective：To observe the clinical effects of ultrasoundguided erector spinae plane（ESP）block on postoperative pain in patients with multiple fractured ribs．Methods：A total of 60 patients with unilateral fractured ribs were randomly divided into 2 groups：ESP group and control group，n=30 in each group.After induction of anesthesia，ultrasoundguided unilateral ESP block were performed in ESP group，while control group received the equal volume of normal saline.All patients received patientcontrolled intravenous analgesia（PCIA）after surgery.Postoperative scores of VAS and PrinceHenry（PH）pain scale were evaluated.The consumption of propofol and remifentanil were recorded，meanwhile PCIA delivered doses and attempts within 48h after surgery were recorded.The adverse effects were recorded.Results：There were no statistical difference in the vital signs and postoperative complications in two groups.Compared with control group the consuption of remifentanil were significantly reduced in ESP group（P＜0.05）.PCIA delivered dose and attempts were significantly reduced in ESP group than control group（P＜0.05）.The VAS scores and PH pain scale at postoperative were significantly lower in ESP group than control group（P＜0.05）.Conclusion：Ultrasoundguided ESP block significantly reduces perioperative opioids consumption，PCIA delivered dose and attempts and can provides good analgesic effects for patients with multiple fractured ribs.

Key words: ultrasoundguided, rib fractures, erector spinae plane block