【Abstract】MicroRNAs are small noncoding RNAs，single stranded in the mature form. microRNAs are post-transcriptional regulators that bind to complementary sequences on target mRNAs，usually resulting in translational repression or target degradation and gene si－lencing. Recent advances in the understanding of lipid metabolism have revealed that microRNAs play major roles in regulating cholesterol and fatty acid homeostasis. MiR-122，the most abundant microRNAs in the liver，is associated with cholesterol metabolism and hepatocellular carcinoma. MiR-33 regulates cholesterol efflux，fatty acid β oxidation，and high-density lipoprotein metabolism. These findings show that microRNAs play an important role in lipid homeostasis and potentially open new avenues for the treatment of dyslipidemias.