Abstract: ObjectiveTo Study the farmilial aggregation in arterioscerotic cerebral infarction.MethodA case-control study including pedig rees(95 cases and 95 controls)was carried out to ex plor e the etiology of family aggr egation of artriosclerotic cerebral infarction in harbin city.ResultsThe family members in both cases and control groups were comparable.The total prevalence rate of the first-pedigree relatives in cases was 16.94%,significantly higher than(3.70%)that noticed in controls,with χ²=81.32(P<0.01).The same results was also found in their parents and siblings.Resultsfrom binominal distribution analysis showed that the number of cases in the farmilies of arter iosclerotic cerebral infar ction was significanlty higher than the therotical range,which indicated that there was significant familial aggregation in the occurance of artcrioselerotic cerebral infarction.Logistic regression model also showed that genetic factor was one of the most important risk factors in harbin city.Dos-eresponse was observed in this model.ConclusionThere was familial ag gregation in arteriosclerotic cerebral infarction.