Abstract: MicroRNAs (micro-ribonucleic acid, miRNAs) are small non-coding RNA molecules, which play an important role in regulating gene transcription. Recent research has found that miRNAs can be used as a new biomarker because of being involved in the progresses of cardiomyocyte development, proliferation and apoptosis. They play an important role in the early diagnosis, prognosis and treatment of acute myocardial infarction. However, there are still many problems and challenges in detection technology, mechanism research and clinical trials of miRNAs.