The clinical manifestations of meningioma are: 1. Most of them are benign with slow growth and long course; malignant with fast growth and short course. 2. Most of them have focal symptoms, such as headache, epilepsy, vision and visual field changes, olfactory or auditory disorders, limb movement and/or sensory disorders. 3.Symptoms of increased intracranial pressure: headache, optic papillar edema, vomiting. 4.Bone thinning or destruction at the site of tumor. The diagnosis is based on: 1. the above clinical manifestations. 2.The density of tumor in CT and the signal intensity of MRI, and its change after enhancement. The tumor is an extracerebral occupancy with clear boundary and intact envelope. The rat tail sign is often formed at the connection between the tumor and the surrounding normal dura on the enhancement film.