Abstract: Objective: In order to know the pathogeny of atrial fibrillation,to discuss the relationship between artial fibrillation and cerebral infarction,and the effect of anti congulation treatment in preventing the generation of cerebal infarction in artial fibrillation patients Methods: Make a record of the pathogeny-discovering rate of heart thrombosis in echocardiography-LEVF-anti congulatin treatment and the generation of cerebal infarction At the same time,make a record of the happening situation of cerebal infarction between the patients with heart disease who have no artial fibrillation and patients without heart disease and artial fibrillation Results: Among 102 cases with artial fibrillation,the common pathogeny is coronary heart disease（59 8%）-hypertensive heart disease（10.8%） cardomyopathy （including congestive and hypertrophic cardomyopathy 6 9%）;the examination of echocardiograpgy shows,3 cases were discovered thombosis in left atrial;the rate of cerebal infarction is 33 3% in artial fibrillation group,the rate of cerebal infarction is 14 6% in heart disease without artial fibrillation group,otherwise,the rate of cerebal infarction is 4 0% in the group with no heart disease no artial fibrillation,P＜0.001;the value of LVEF is 48. 9% 5 8 and 49. 3% 4 7,P ＞ 0.05 respectively in artial fibrillation and heart disease without artial fibrillation group;the rate of cerebal infarction is 22 4% and 43. 4%P＜0.001 respectively in transient artial fibrillation and continuous artial fibrillation;in continuous artial fibrillation group,the rate of cerebal infarction is elevated as well as time goes on,the period shorter than 1 year,the rate is 25 0%,1~3 year the rate is 45 8%,longer than 3 year the rate is 52. 9%,P＜0.005;the rate of cerebal infarction is 52. 4% and 37. 5%,P＜0.005respectively in patients with continuous artial fibrillation who never or occasionally use anti congulation treatment and long term use anti congulation treatment Results: Artial fibrillation is one of dangerous reasons in the happening of cerebal infarction,and anti congulation treatment can reduce this kind of danger