Objective: To investigate the influences of hepatitis C virus (HCV) proteins NS3, Core and NS5A on RASSF2 mRNA expression and methylation status of RASSF2A promoter in hepatic cells. Methods: The RASSF2 mRNA expressions in hepatic cells respectively transfected with NS3-, Core- and NS5A-expression plasmids (NS3/QSG7701, Core/QSG7701 and NS5A/QSG7701) as well as normal hepatic cell line L02 were determined by RT-PCR method. The methylation statuses of RASSF2A promoter in NS3/QSG7701, Core/QSG7701 and NS5A/QSG7701 cells were examined by methylation-specific PCR, and the changes in their RASSF2 mRNA expressions and biological behaviors after treatment with demethylation agent 5-aza-dC were observed. Results: The RASSF2 mRNA expressions were significantly decreased in all NS3/QSG7701, Core/QSG7701 and NS5A/QSG7701 cells compared with L02 cells (all P<0.05), and the RASSF2A promoters were fully methylated in all the three types of cells. After 5-aza-dC treatment, the RASSF2 mRNA expression was upregulated in NS3/QSG7701 and Core/QSG7701 cells (both P<0.05), but did not change in NS5A/QSG7701 cells (P>0.05); the proliferation rate was decreased and apoptosis rate was increased in NS3/QSG7701 and Core/QSG7701 cells5-aza-dC treatment (both P<0.05). Conclusion: NS3, Core and NS5A can reduce RASSF2 expression through RASSF2A promoter methylation and also through other mechanism by NS5A. This effect may probably contribute to the carcinogenesis of HCV-associated hepatocellular carcinoma.