The overexpression of miRNA-34a was used to detect the expression of Bcl-2 and its effect on the growth and migration of liver cancer cells, and provided a new target for the treatment of liver cancer.Methods The potential targets of miRNA-34a were predicted by bioinformatics. The targeted regulation relationship between miRNA-34a and Bcl-2 was detected by double luciferase reporter experiment Hepatocellular carcinoma cells were cultured in vitro and transfected with miRNA-34a mimetic and negative control respectively. After 36 hours of transfection, CCK8 was used to detect cell proliferation, Trans well was used to detect cell migration ability, and q-PCR and Western blot were used to detect the effect of miRNA-34a on Bcl-2 expression in hepatocellular carcinoma cells. Results miRNA-34a could directly down regulate the expression of Bcl-2 (P＜0.01). MiRNA-34a could inhibite the viability and migration of hepatocellular carcinoma HepG2 cells (P＜0.01). Conclusion MiRNA-34a can target and negatively regulate Bcl-2 to reduce the activity and migration ability of HepG2 cells.