Benign intracranial tumors are tumors that grow in one part of the skull (mostly outside the brain nerve tissue), have good cell differentiation, grow slowly, and are mostly curable. On the contrary, malignant intracranial tumors (most of them grow inside the neural tissue of the brain) are poorly differentiated, grow rapidly and are difficult to be cured. Some benign intracranial tumors, due to their deep location and many important structures around them, are already large in size when they are found, so they cannot be removed completely by surgery and have poor prognosis. Some of the so-called intracranial malignant tumors, however, can be removed almost completely because they grow in less important brain tissues, and can survive for a long time or even be cured after surgery. There are very few brain tumors that start as benign and later turn malignant. Intracranial glioblastomas, metastases and invasive tumors are mostly malignant. Meningiomas, pituitary adenomas, embryonic residual tumors and vascular tumors are often benign. However, most of them are difficult to be cured. Malignant brain tumors have short course and fast development, and recurrence can be early or late depending on the degree of malignancy, the number of surgical resection or the sensitivity of radiotherapy. The average survival rate of benign brain tumors is less than one year after surgery for radiation and chemotherapy, and for benign glioma, pituitary tumor, craniopharyngioma, cholesteatoma, etc. It is not easy to remove benign intracranial tumors, and gamma knife, X-ray knife and radiation therapy cannot kill the tumors completely, so most patients will still have recurrence after surgery.