Abstract:AimThe endoplasmic reticulum (ER) is an organelle involved in protein folding, calcium homeostasis, and lipidbiosynthesis.Various factors that interfere with ER function disrupt ER homeostasis,which result in ER stress.The unfolded protein response(UPR) is initiated to adapt to the changing environment, and reestablish normal ER homeostasis.Prolonged and excessive ER stress triggers cell suicide, usually in the form of apoptosis, and plays an important role in many diseases.It is found in recent studies that ER stress is involved in the pathogenesis of injured vascular diseases such as atherosclerosis, hypertension, vascular calcification, and restenosis.Here, we reviewed recent progresses in ER stress and injured vascular diseases.