In the first report, the clinical manifestations of 30 cases of the lateral ventricle tumor were reviewed. This report summarizes neuroradiological findings of the same 30 cases, in which 26 cases were examined by cerebral angiograms and 3 cases by CT scan. For the radiological analyses, the tumors of the lateral ventricle are classified into two groups, as follows: 1. Intraventricular tumors arise in the projection of the choroid plexus, the tela and the ependyma and grow in the lateral ventricle. 2. Paraventricular tumors arise from the wall of the neuroglia not only bulge into ventricle, but in addition infliltrate the substance of the surrounding brain. Following conclusions are obtained. (1) Unilateral hydrocephalus, which is shown clearly by vascular displacements in subependymal veins, is demonstrated in both tumors groups. (2) There are different findings on the feeding arteries, the draining veins and the tumor stains between two tumors groups. (3) In the intraventricular tumors groups, the anterior choroidal artery supplying the tumor is its the plexal segments and atrial segments. (4) On the other hand, the paraventricular tumors group, the anterior choroidal artery supplying the tumor is its the superior penetrating branch to the cerebral parenchyma. (5) Cerebral angiograms can reveal the definite signs of the intraventricular mass, but it is sometimes difficult to evaluate whether its space occupying lesions infiltrates the cerebral substance below the wall of the lateral ventricle, or not. (6) CT scan is useful neuroradiological method in the different diagnosis between two tumor groups, and CT scan provides and anantomical diagnosis rather than a histological one. (7) The accurate diagnosis of the tumors of the lateral ventricle can be demonstrated by both cerebral angiograms and CT scan.