Abstract: Patients with primary chronic venous disease (CVD) often suffer from heaviness,swelling and pain of the lower limbs together with stasis dermatitis and ulcer of the boot-covered area in legs.CVD is highly prevalent in populations.Internationally,the diagnosis of CVD has progressed from a clinical impression based upon physical examination to an image-based precise process.In 1994,the American Venous Forum developed a venous disease assessment tool,the clinical-etiology-anatomy-patho physiology (CEAP)classification,to standardize the diagnosis of CVD,which was updated in 2004.The classification system has improved the diagnosis of CVD,and enhanced the comparability of research reports on primary venous diseases.