The present invention provides a method for replicating efficiently an RNA containing fulllength HCV genomic sequence and a method for producing HCV virus particles containing fulllength HCV replicon RNA or fulllength HCV genomic RNA by using a cell culture system. Further, the present invention relates to a method for producing hepatitis C virus particles which comprises culturing a cell, into which a replicon RNA comprising a nucleotide sequence comprising a fulllength genomic RNA sequence of hepatitis C virus of the genotype 2a, at least one selectable marker gene and/or at least one reporter gene and at least one IRES sequence or the fulllength genomic RNA of hepatitis C virus of the genotype 2a is introduced, and generating virus particles in the culture medium. Still further the present invention relates also to a hepatitis C vaccine and an antibody against hepatitis C virus particles.