【】Objective To observe the analgesic effect and safety of ultrasound-guided pectoral muscle block in mastectomy. Methods From January 2017 to January 2018, Sixty patients, American Society of Anesthesiologists(ASA)Ⅰ－Ⅱ, aged 28－59 years, scheduled for unilateral open inguinal herniorrhaphy were equally and randomly assigned to ultrasound-guided nerve block group (N group) or Local anesthesia group (Group L) using randomization table(n=30).. The patients in group N received ultrasound-guided unilateral paravertebral block with 20 mL 0.5% ropivacaine respectively. In the group L, along the surgical shuttle incision layer injection of local anesthetic 1% lidocaine 20mL. Heart rate (HR), and mean arterial pressure (MAP) were recorded at the time of entering the operating room ,skin incision ,removing breast lumps and skin suture. Visual analogue scale (VAS) scores at 2h, 4 h, 8 h,12 h after surgery were recorded. the number of cases of using sufentanil , respiratory depression, nausea, vomiting, nerve damage, and local anesthetic poisoning were recorded in both groups. Results The vital signs during the operation in the N group,were more stable than those in the L group (P < 0.05). VAS scores in the group N was significantly lower than the L group at 4, 8, and 12 h after operation (P < 0.05). There was no significant difference in VAS scores at 2 h after surgery between the two groups(P > 0.05). The number of fentanil in group N was significantly less than in group L (P < 0.05). There were neurological injury and local anesthetic poisoning symptoms. There was no significant difference in postoperative respiratory depression, nausea and vomiting between the two groups (P > 0.05). Conclusion Ultrasound-guided chest muscle nerve block can fully meet the breast Anesthesia for lumpectomy surgery requires longer analgesia and is safer and more effective.