INTRODUCTION With the development of economy and improvement of life quality,the incidences of hypertension,hyper-cholesterolemia,diabetes,obesity and smoking have been increased in China,which has led to a significant increase in the morbidity and mortality of coronary artery disease (CAD) 1.Since it was introduced into China in 1984,coronary intervention (PCI) has developed rapidly and has become the major treatment of CAD because of its unique characteristics of minimal invasive and effective outcome.