Objective To examine the distribution characteristics the medial branch of the posterior branch of the spinal nerves around the lumbar facet joints, so as to explore the localization and targeting of the medial branch of the posterior branch in neurectomy.MethodsFive corpses were dissected, and the anatomical relationships between the medial branches of the posterior branch of the spinal nerves and the facet joints were examined.Measured the distances from the lateral port of the bone fiber tube,the articular process of the facet joint and the superior articular process to the spinous processes.Results The medial branch of the posterior branch of the spinal nerve was close to the root of the articular process and the transverse process,which was not easy to be explored and dissected.Meanwhile, it was easily traced after the medial branch of the posterior branch of the spinal nerve ran through the fibrous tube.Conclusion It may improve the safety and effective when the techniques of medial branch block is performed after the medial branch ran through the fibrous tube.