Emergency coronary angiography of a 53-year-old man with acute coronary syndrome revealed stenosis in right coronary artery. During angioplasty, the ECG change showed three kind of ST deviation, namely inferior ST elevation with precordial ST depression, inferior ST elevation with precordial ST elevation, and inferior ST depression with precordial ST elevation. The present case shows that the ST deviation of the inferior ischemia with right ventricular ischemia takes various patterns. This phenomenon is decided by degree of right main coronary and right side branch blood flow.