Objective  To study anatomic features of the lumbosacral multifidus muscle and provide reference for reducing spinal injury during posterior lumbar surgery.  Methods  25 corpses were dissected. The origin, insertion, the construction of muscle bundle, and the relationship with adjacent structures of multifidus muscle were observed and measured. Results   The superficial part of the multifidus muscle originated from long sacroiliac ligament, and the medial side of posterior superior iliac spine, however, the deep ones from the sacral plank and sacroiliac short ligament. The width of short tendon of L1-5 multifidus muscle were respectively (15.10±2.43), (15.68±2.79), (14.82±2.77), (14.16±3.62) and (11.58±2.46)mm. The width of it were respectively (4.72±0.99), (5.42±1.14), (5.86±0.99), (5.90±1.06) and (4.68±0.62)mm.  Conclusions   Multifidus muscle is one of key elements to keep the stability of the spine, for it participates in the dorsal extension of vertebral column and the maintenance of lumbar spine lordosis.