micro RNAs(mi RNAs or mi Rs) are small non-coding RNAs that are involved in posttranscriptional regulation of their target genes in a sequence-specific manner. Emerging evidence demonstrates that mi RNAs are critical regulators of lipid synthesis, fatty acid oxidation and lipoprotein formation and secretion. Dysregulation of mi RNAs disrupts gene regulatory network, leading to metabolic syndrome and its related diseases. In this review, we introduced epigenetic and transcriptional regulation of mi RNAs expression. We emphasized on several representative mi RNAs that are functionally involved into lipid metabolism, including mi R-33/33 n, mi R122, mi R27a/b, mi R378/378 n, mi R-34 a and mi R-21.Understanding the function of mi RNAs in lipid homeostasis may provide potential therapeutic strategies for fatty liver disease. MicroRNAs (miRNAs or mi Rs) are small non-coding RNAs that are involved in posttranslational regulation of their target genes in a sequence-specific manner. Emerging evidence demonstrates that miRNAs are critical regulators of lipid synthesis, fatty acid oxidation and lipoprotein formation and secretion. Dysregulation of miRNAs disrupts gene regulatory network, leading to metabolic syndrome and its related diseases. In this review, we introduced epigenetic and transcriptional regulation of mi RNAs expression. We emphasized on several representative mi RNAs that are functionally involved in lipid metabolism, including mi R-33/33 n, mi R122, mi R27a / b, mi R378 / 378 n, mi R-34 a and mi R-21.Understanding the function of mi RNAs in lipid homeostasis may provide potential therapeutic strategies for fatty liver disease.