Abstract: Objective To explore the effect of microRNA-221-3p(miR-221-3p) on the proliferation of hepatocellular carcinoma(HCC) cells and underlying mechanism.Methods Bioinformatics database were used to analyze the expression of miR-221-3p in hepatocellular carcinoma and its relationship with patient prognosis. The effect of miR-221-3p on the proliferation of HCC cells were analyzed by EdU and CCK-8 assays. Bioinformatics and Western blot were used to investigate the role of miR-221-3p in regulating the proliferation of HCC cells.Results The level of miR-221-3p was up-regulated in HCC, which was not correlated with overall survival. The proliferation of HCC cells was attenuated by miR-221-3p silencing but enhanced by miR-221-3p overexpression. MiR-221-3p activated the JAK2/STAT3 signaling pathway through negatively regulating vestigial-like family member 4(VGLL4).Conclusions Mir-221-3p can promote the proliferation of HCC cells, which may be related to its negative regulatory effect on VGLL4 and further activation of the JAK2/STAT3 signaling pathway.