Objective: To investigate the expression levels of miR-199a-5p in the liver under various nutritional conditions and its effects on hepatic triacylglyceride (TAG) content, as well as the underlying mechanisms. Methods: Quantitative real-time PCR (RT-qPCR) was used to detect the expression of miR-199a-5p in liver tissues of high fat diet (HFD) mice. Hepa1-6 and AML12 cells were transfected with miR-199a-5p mimics, inhibitors, negative controls and pcDH-CD36-flag plasmid, respectively. The changes in gene expression related to lipid metabolism were detected by RT-qPCR and Western blot, and TAG content was detected by kit. The Target gene of miR-199a-5p was predicted by miRDB (microRNA Target Prediction Database) and verified by dual luciferase reporting assay.Results: The expression levels of miR-199a-5p in the liver of C57BL/6J mice were elevated under high-fat diet and fasting conditions. Overexpression of miR-199a-5p reduced TAG levels in hepatocytes, while inhibition increased intracellular TAG content. miR-199a-5p decreased the protein expression of the fatty acid translocase (CD36) by interacting with its 3′ untranslated region（3' UTR）. Conclusion: The expression level of miR-199a-5p increases during hepatic lipid accumulation, and miR-199a-5p may reduce TAG content in hepatocytes by targeting CD36.