Hydrogen sulfide (H2S) is involved in cancer biological processes. However, there are several controversies concerning the role of H2S in cancer development and progression. In this study, we found that the growth and migration of hepatocellular carcinoma (HCC) cells were enhanced by 10-100 μM NaHS and dose-dependently inhibited by 600-1000 μM NaHS. The apoptotic levels were reduced by 25-100 μM NaHS but increased by 400-1000 μM NaHS in HCC cells. After treatment with 25-50 μM NaHS, the protein levels of p-EGFR, p-ERK, MMP-2, and p-AKT were increased, whereas the levels of PTEN and the ratio of BAX/BCL-2 were down-regulated. Administration of 800-1000 μM NaHS showed opposite effects on these protein levels in HCC cells. However, H2S showed no effects on the growth, migration, apoptosis, and the protein levels of the EGFR/ERK/MMP-2 and PTEN/AKT signaling pathways in L02 cells. Furthermore, 25-100 μM NaHS promoted HCC tumor growth and blood vessel formation, while 800-1000 μM NaHS inhibited angiogenesis and tumor growth with no obvious systemic toxicity. These results indicate that H2S acts as a double-edged sword in HCC cells through EGFR/ERK/MMP-2 and PTEN/AKT signaling pathways. Novel H2S donors could be designed and applied for further antitumor research.