In order to explore the role of core protein on the replication and infection of hepatitis C virus (HCV), intergenotypic chimeric FL-J6JFH/J4 core replicon was constructed in which the core gene of Fl-J6JFH strain (genotype 2a) was replaced by corresponding gene from HC-J4 strain (1b). In vitro RNA transcripts of FL-J6JFH and FL-J6JFH/J4 core were prepared and transfected into Huh7.5.1 hepatocytes respectively with liposomes. At day 5 post-transfection, total cellular RNA was isolated and determined by fluorescence quantitative polymerase chain reaction (FQ-PCR) method. Immunofluorescence staining analysis was performed to test the expression of HCV proteins in transfected cells at day 8 post-transfection. The naïve Huh7.5.1 cells were inoculated with the supernatants collected at day 8 post-transfection, and HCV proteins were detected by immunofluorescence at 72 h after inoculation. The results demonstrated that, the intracellular HCV RNA values of FL-J6JFH/J4 core was close to that of wild-type FL-J6JFH1 at day 5 post-transfection, and no significant differences were observed (n＝4, P>0.05). Immunofluorecene analysis showed that, as compared with that in the wild type cells, the expression of HCV proteins in either cells transfected with FL-J6JFH/J4 core RNA at day 8 post-transfection or inoculation with supernatants collected at day 8 post-transfection was significantly lower. The results suggest that the core gene substitution among different HCV strains might influence the HCV protein expression and the production of infectious viral particles.