Protein disulfide isomerase (PDI) is one of thiol-disulfide oxidoreductases that mainly located in the endo?plasmic reticulum (ER). It is generally known that PDI caralyzes the formation,rearrangement,breakage of disulfide bonds, and this enzyme is effective in regulation of protein folding. Now it is also known as a biomarker of cardiovascular disease. Protein disulfide isomerase can reduce infarct size and myocardial apoptosis in acute myocardial infarction (AMI). PDI can also improve changes of cardiac vulnerability in diabetic cardiomyopathy (DCM). Further more, it is also shown that PDI play an important role in hypertension and thrombosis. Therefore, this paper review the effects of protein disulfide isomerase in cardiovascular diseases.