Micro RNA (miRNA) are short about 19～22 nucleotides long noncoding RNA.They were isolated from plasmas from well-characterized patients with varying degrees of cardiac damage: acute myocardial infarction.More and more research show miRNA are novel biomarkers for cardiovascular diseases.Disease of the myocardial infarction is the most common cardiovascular defect and causes of adult morbidity and mortality.An early diagnosis may ensure immediate initiation of reperfusion therapy to potentially reduce the death rate.To compare the plasma of miRNA between healthy people and patients with acute myocardial infarction, it can be found that the plasma level of miRNA in patients with acute myocardial infarction are raised significantly.