To investigate whether miR-199a-3p targets YAP1, and downregulates Jagged1 to inhibit proliferation and promote apoptosis of HCC cells, we firstly upregulated miR-199a-3p and downregulated YAP1 by transfecting miR-199a-3p mimics, si-YAP1 and their respective controls into Huh7 cells, respectively, and observed the expression of Jagged1 protein. This evidence concerns the gene YAP1 and hepatocellular carcinoma.