The endothelial glycocalyx (EG) is a polyglycoprotein complex present on the internal vascular surface, and its impairment is associated with the progression of multiple diseases, including atherosclerosis, stroke, sepsis, diabetes, kidney disease, hypertension, and lung edema. Therefore, glycocalyx health can be used as a biomarker to evaluate vascular health. Aging leads to dysfunctional changes in the glycocalyx; for example, its thickness decreases, and the genes of enzymes involved in its synthesis and digestion are dysregulated. As a natural barrier to the vascular system, age-related glycocalyx disruption is associated with vascular dysfunction, including impairment of vascular contraction and dilation, enhancement of permeability, dysregulation of inflammatory and immune reactions, and imbalance of anticoagulation and thrombin. From the perspective of ‘structure determines function’ studies on the changing regularity of the thickness, components, microstructure, and mechanical properties of EG with aging and its relationship with vascular dysfunction are of great significance for the prevention, diagnosis, and treatment of atherosclerosis and other age-related cardiovascular diseases.