Objective To investigate the clinical effect of external ventricular drainage on the prognosis of anterior communicating artery aneurysms.Methods Retrospectively collected and analyzed 96 patients of anterior communicating artery aneurysms who were treated in our hospital from June 2013 to October 2015,and they were divided into the observation group which was given external ventricular drainage treatment and the control group which was not given external ventricular drainage treatment.These patients were followed up for 6 months to 2 years,and the results of the 2 groups were graded according to the analysis of postoperative complications and the Glasgow prognostic score (GOS).Meanwhile,evaluated the general function of the patients according to the KPS score.Results The the incidence rate of complications after treatment in observation group was 54.17％,which was lower than 86.96％ in the control group,and the difference was statistically significant(P ＜ 0.05).The cure rate of observation group was 79.16％,which was higher than 50％ in the control group,and the difference was statistically significant (P ＜ 0.05).The postoperative KPS score in the observation group was (79.68 ± 13.24) points,which was higher than (62.57 ± 12.72) points in the control group,and the differences were statistically significant (P ＜ 0.05).Conclusion External ventricular drainage can reduce the compression injury of the brain tissue to a minimum degree,reduce intracranial pressure,relieve cerebral edema caused by intracranial pressure,reduce complications,and improve the prognosis of patients and the cure rate.