<p>Disclosed are: a hepatitis C virus (HCV) gene which has higher replication efficiency and higher reinfection efficiency than those of a known HCV gene having a genotype 1b; an RNA replicon which carries the gene; a cell which is infected by the RNA replicon and can replicate an HCV; and an HCV particle. The HCV gene is characterized in that the 979th amino acid encoded by the gene is threonine, the 1804th amino acid encoded by the gene is leucine and the 1966th amino acid encoded by the gene is lysine. It becomes possible to provide an HCV gene which can be proliferated in vitro and has higher replication efficiency and higher reinfection efficiency than those of a known HCV gene having a genotype 1b.</p>
