Quadratus lumborum block(QLB)is a regional anesthesia technique that provides sen-sory and sympathetic nerves block of the unilateral trunk and lower limb by an injection of local anesthetic into the fascia space around the quadratus lumborum.At present,ultrasound-guided QLB is widely used in postoperative analgesia in abdominal and lower limb surgery with satisfied analgesia efficacy.This article will review the anatomical basis,mechanisms,puncture approaches,local anesthetic selection,clinical applica-tion and complications of QLB.