Cerebrovascular malformation and cerebral aneurysm are the two most common hemorrhagic cerebrovascular diseases other than hypertensive cerebral hemorrhage. They belong to the category of cerebrovascular disease, but there are great differences in pathogenesis, symptoms and treatment prognosis. In cerebrovascular malformation, arteriovenous malformation accounts for about 95%, now it is thought that the original arteries and veins are parallel in the embryonic stage of brain, separated by only two layers of vascular endothelial cells, if communication occurs between the two, blood flow directly from the arteries into the veins, forming a short circuit of blood flow, and then forming an abnormal malformed vascular mass. Depending on the artery and vein supplying the malformation and the location of the malformation, patients may have different symptoms. For example, epilepsy, headache, limb movement disorder, cognitive dysfunction, proptosis, etc. Cerebral aneurysm is a localized abnormal enlargement of cerebral vessels, which can be classified as congenital, bacterial, traumatic, tumor and atherosclerotic according to the cause. Most aneurysms are located around the bifurcation of large blood vessels on the brain surface. Unruptured aneurysms are usually asymptomatic and are often detected by dizziness and headache during examination. The greatest risk of cerebrovascular malformation and aneurysm lies in their rupture and bleeding, which is often followed by sudden and severe headache, nausea, vomiting, impaired consciousness and other typical symptoms. The difference between the two is that the rupture and bleeding of cerebrovascular malformation is more likely to result in convulsions and neurological deficits than the rupture and bleeding of aneurysm because the malformation mass is mostly located in brain tissue and the bleeding location is mostly located in brain parenchyma. Some cerebrovascular malformations rupture and bleed due to the presence of “aneurysm-like structures” (not aneurysms as described above) within the structures, which are also formed due to the action of higher blood flow on locally developed abnormal blood vessels, mostly located on the blood supply arteries of the malformed mass rather than on the bifurcation of large blood vessels. How do you determine which disease is present? The most definitive and reliable means of diagnosing this type of cerebrovascular disease is currently considered to be cerebral angiography. The results of the angiography not only clarify the type of lesion, but also allow us to understand the local structure of the lesion through 3D reconstruction and other techniques, which is the prerequisite and basis for deciding on the next treatment plan. Only through imaging can we determine which option is safer and more effective for the patient: craniotomy or interventional treatment. For the interventional treatment of cerebrovascular malformations alone, embolization should be considered for lesions that are deep and located in important functional areas or with high blood flow, but embolization alone may only partially cure the lesion, and microsurgery or radiation therapy can be performed after partial embolization. Before the lesion is completely eliminated or occluded, the patient is at risk of rebleeding. Therefore, for vascular malformations that cannot be completely embolized, embolization of aneurysm-like structures and other structures prone to rupture and bleeding should be considered first to reduce the patient’s risk of bleeding. For patients with cerebrovascular malformations combined with intracranial aneurysms, the risk of rupture and bleeding of both should be carefully evaluated based on cerebral angiography and other examinations before deciding which treatment plan is safer and more effective. For stereotactic radiotherapy (γ-knife, X-knife), we believe that it is more suitable for the treatment of smaller (≤2.5-3 cm), deep or residual cerebrovascular malformations after surgery and intervention. In general, radiation therapy requires 1-2 years before the therapeutic effect can be observed. The nature of radiotherapy also determines its ineffectiveness and risk in treating cerebral aneurysms and aneurysmal-like structures within cerebrovascular malformations.