Atherosclerotic lesions are always vascularized by a network of capillaries which are important regulators of plaque instability. Associated with the increased number of capillaries, the accumulation of lipids and inflammatory cells may attenuate the fibrous cap and cause plaque rupture. As a result, the probability of cardiovascular events increases. Recent researches about miRNA convinced us that miRNAs played a key role not just in tumor but also in atherosclerosis. Discoveries of atherosclerosis-related miRNAs also provoked many thoughts about the diagnosis and treatment of cardiovascular diseases.