Objective  To reveal the anatomical structure of the atlantooccipital region and to provide accurate anatomical data for clinical operation.    Methods  Eight cadavers were selected for cranial base tissue blocks, these blocks were plastinated and cut into serial sections. After staining,these sections were examined under an optical microscope.   Results  The odontoid tip was mainly spongy bone, the lower part of odontoid process was mainly compact bone substance. The apical ligament of dens was a small bundle of cord fibers connecting the apex of dens and the anterior margin of the foramen magnum. The tectorial membrane was a tough film which descends from the occipital slope, after the upper and lower longitudinal fascicles of the cruciate ligament, closely associated with the axis. The front of the spinal dura mater was covered with the tectorial membrane, and the rear was arachnoid. The spinal dura mater joins with the tectorial membrane from the clivus and moves down warded to the lowest part of the anterior margin of the foramen magnum to separate and continue their respective downward course. At the position of the dens, the spinal dura mater joined with the tectorial membrane again and travelled down to C2 vertebral body to separate. The tectorial membrane covered the posterior longitudinal ligament at the level of the odontoid tip.    Conclusion  The Barkow ligament may not be present and may not be used as a marker during clinical surgery.