Abstract: MicroRNAs( miRNAs) are small nucleotide sequences that regulate gene expression. Studies show that miRNA can maintain body homeostasis,regulate the physiological function of eukaryotic cells,and participate in a variety of pathological pathways. Many studies prove that miRNAs play an important role in heart disease. Recent research of miRNAs aimed at finding new targets for the treatment of heart disease has achieved rapid development. This paper systematically reviews the functions of miRNAs in heart disease and discusses the related molecular mechanisms.