目的：探讨外部性脑积水（EH）的发展规律及预后情况。材料与方法：选择资料完整的EH63例，分别在3个月、6个月、9个月、1岁、2岁和3岁时进行头颅CT复查。结果：EH可以在生后数天发生，3～6个月时为EH的典型期，9个月～1岁时开始好转恢复，2岁前基本恢复正常。CT征象上，恢复正常的顺序依次为蛛网膜下腔、鞍上池、环他和纵裂池，外侧裂恢复最慢。结论：①EH为一自限性病征，多在2岁前恢复正常。②抽搐与EH的严重程度密切相关。 Objective: To investigate the development and prognosis of external hydrocephalus (EH). Materials and Methods: EH63 cases with complete data were selected and skull CT was performed at 3 months, 6 months, 9 months, 1 year, 2 years and 3 years respectively. Results: EH occurred within a few days after birth, typical period of EH at 3-6 months, recovery from 9 months to 1 year old, and recovery to normal before 2 years old. CT signs, the order of return to normal followed by the subarachnoid space, suprasellar cistern, ring him and longitudinal split pool, lateral fissure recovery the slowest. Conclusion: ①EH is a self-limiting disease, mostly returned to normal before the age of 2 years. ② seizures and the severity of EH are closely related.