We examined 984 objects for exercise stress test, using CASE I(computer assisted system for exercise). They exercised according to Bruce's protocol, Among them, the mal were 613 and the female were 371. (Male:Female;17:1) The 5th and 6th decades occupied 61% of total objects. The purpose of test was evaluation of chest pain in 84% of total cases. The most frequent end point of test was dyspnea(42%) and chest pain was observed in 13% of total cases. Most of all objects above 8-9 METS. Positive results of exercise stress tert were obtained in 23%. As complications, ventricular tachycardia occurred in 7 cases, supraventricular tachycardia; 8, high degree VPB's; 6, sudden cardiovascular collapse;15, The complication rate was 0.36% but morbidity and mortality were 0. All complicated cases recoved spontaneously only by rest.