To delineate the coronary anatomy and left ventricular function during early myocardial infarction, coronary arteriography and left ventriculogrphy were performed, prospectively in 23(22%) of 105 patients who were admitted to the coronary care unit at Masan Koryo Hospital from June 1986 to June 1988 within 4 weeks after the onset of symptoms(medium:21 days, range:18 days to 25 days). 1) Among 23 patients, male is 20 patients and female is 3 patients. The ratio of male to female was 6.6:1. The mean age was 55.4+/-10.3 years(range:34-77 years). 2) Coronary artery narrowing state which related to myocardial infarction was as follows; 2 patients(7%) had normal, 1 patients(4%) had insignificant narrowing(below 50%) 5 patients(22%) had moderate narrowing(50-75%), 10 patients(43%) had severe narrowing(75-99%), 5 patients(22%) had complete occlusion(100%). 3) The range of coronary artery disease was as follows; 9 patients had one vessel disease, 10 patients had two vessel disease, 1 patients had three vessel disease, and ejection fraction had no significant difference among 3 groups but lowest in three vessel disease. Among 23 patients, 13 patients had anterior infarction, 10 patients had inferior infarction. 4) Left ventricular ejection fraction and multiple vessel disease had no significant difference between i) the young(under 45 years old) and the old(over 45 years old) age groups, ii) presence or non presence of previous angina, iii) Killip classification I, II and III, IV) anterior infarction and inferior infarction. 5) In left ventriculography, akinesis and dyskinesis were shown at similar ratio in anterior infarction and inferior infaraction. Dyskinesis was shown in 27% of patients who have 0-1 vessel disease, 50% of patients who have 2-3 vessel disease, 62% of patients who have collateral circulation, 26% of patients who dose not have collateral circulation. 6) Collateral circulation was found in 8 patients(35%). Age and left ventricular ejection fraction were high in patients without collateral circulation than with collateral circulation, but there is no significant difference and collateral circulation exists regardless of infarction site and range of coronary artery disease. 7) As for the complication of angiocardiography in this study, there was ventricular tachycardia in 3 patients(13%) without mortality. It is concluded that coronary arteriography can be safely performed in early stage after acute myocardial infarction. Also good prognosis is anticipated since three vessel disease and complete occlusion were low in acute myocardiaol infarction of Korean People. Since these are not much case performed study, however more study on this area is required.