Causes of subarachnoid arcuate notching in the cervical spine include bony encumbrance production, cervical disc herniation, ossification of the posterior longitudinal ligament. and tumors of the cervical vertebral body. Cervical vertebral degeneration caused by cervical vertebral osteophytes, cervical intervertebral disc herniation, and ossification of the posterior longitudinal ligament will protrude into the vertebral canal, resulting in the formation of an arcuate indentation in the subarachnoid space, and there are also some indentations that show irregularity, which is due to the damage of the posterior longitudinal ligament of the cervical vertebrae or the protrusion bypassing the posterior longitudinal ligament. A cervical vertebral tumor protruding backward may compress the posterior longitudinal ligament to form an arcuate indentation. CT scan, X-ray or magnetic resonance imaging of the cervical spine may assist in the diagnosis. If the cervical degeneration leads to cervical subarachnoid impingement, there is no symptom and no treatment is needed, but if it is caused by tumor, active treatment is needed. Cervical subarachnoid space arcuate indentation may also have other causes, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, and then give targeted treatment or therapy.