Abstract: MicroRNAs (miRNAs) are a class of small ( 21-25 nt), endogenous and noncoding RNAs. MiRNAs act as crucial regulators of a wide range of physiological and pathological processes including cell proliferation, growth, differentiation and apoptosis. Recent studies have revealed distinctive patterns of circulating miRNAs in myocardial infarction, heart failure, atherosclerotic disease and hypertension. These circulating miRNAs may therefore be used as potential diagnostic biomarkers and therapeutic targets of cardiovascular diseases.