Inclusion Criteria:  Age: greater than 20, less than 75 Patients with significant coronary artery disease (diameter stenosis >70%) requiring coronary revascularization Reference vessel diameter: between 2.5 and 4.0 mm Obtained informed consent from voluntary participants before study enrollment  Exclusion Criteria:  Complex coronary lesion (ostial lesion, unprotected left main lesion, chronic total occlusion, grafted vessels, etc) Reference vessel diameter: less than 2.5 mm, greater than 4.0 mm Coronary lesion with heavy calcification Hemodynamic instability during coronary intervention Contraindication to antithrombotic therapy Chronic renal insufficiency (Serum creatinine >2.0mg/dL) Severe liver dysfunction (AST/ALT > 5 times of upper normal limit) Pregnancy or potential pregnancy Life expectancy less than 1 year Patient refused to sign the informed consent at enrollment