Symptoms of syndrome X are symptoms of angina pectoris, or angina-like symptoms. The main symptoms are chest tightness, chest pain, panic or shortness of breath in the precordial region after activity or unrelated to activity. In this group of patients, the exercise stress test is often positive, but the coronary angiography is negative, the large coronary vessels are fine, but there are symptoms, mainly related to microcirculatory disorders and endothelial dysfunction. Clinically, there is often no specific treatment for these patients, and some of our commonly used anti-anginal drugs such as nitrates, trimetazidine or some Chinese preparations, or secondary prevention drugs for coronary artery disease, are of little use to these patients.