Diabetes mellitus is a worldwise disease affecting millions of persons. The high prevalence of cardiovascular disease among diabetics is well known. And vascular disease is well established as a leading cause of death among diabetics since insulin and antibiotics have done much to combat some of the other causes (JosIin at al). So we investigated the cardiovascular complications among the 634 diabetics admitted to Severanee hospital from January, I963 to December, 1969, and the following results were obtained. 1) Among the cardiovascular compfications of diabetics hypertension was the most common (28.2%), and arteriosclerosis had a frequency of 9, 6%, myocardial isahemia 5. 0%, myocardial infretion 2.3% and gangrene 1. 4%, Also, Above frequencies were higher than of general population in Korea. 2) The frequency of cardiovascular complications increased as the age became older, and as the duration of diabetes mellitus became longer. 3) The group with higher level of serum cholesterol had the higher frequency of vascular complications. 4) The varisnce of the level of serum cholesterol along the duration of diabetes and the level blood sugar on admission were not significant. 5)The variance of frequency of eardiovascolar complications along the level of F.B.S. on admission was not significant also.