本文分析了６４例颅内动脉瘤全脑血管造影资料，就大脑后动脉内侧段异常在后交通动脉所占的比率，与后交通动脉瘤的关系及与性别、年龄的关系进行了探讨。指出大脑后动脉内侧段异常（ＡＩＳ－ＰＣＡ）是发生后交通动脉瘤（ＰｃｏＡＡ）血流动力学变化的重要因素之一，而女性及动脉粥样硬化是引起大脑后动脉内侧段异常的重要因素之一。强调了大脑后动脉内侧段异常对后交通动脉瘤的影象诊断及外科治疗的意义 This article analyzes 64 cases of intracranial aneurysm cerebral angiography data on the medial posterior cerebral artery anomalies in the proportion of posterior communicating artery, and the relationship between posterior communicating artery aneurysms and sex and age were discussed. It is pointed out that AIS-PCA is one of the important factors in the hemodynamic changes of post-operative aneurysm (PcoAA). Female and atherosclerosis are important factors that cause the abnormality of medial segment of posterior cerebral artery one. Emphasizes the significance of diagnosis and surgical treatment of posterior communicating artery aneurysm by abnormal medial segment of posterior cerebral artery