This invention relates to a nucleic acid comprising a nucleic acid sequence encoding an epitope tag peptide in the hypervariable region 1 of the E2 protein of naturally occurring or chimeric hepatitis C virus (HCV) genome, an epitope-tagged HCV particle encoded by such nucleic acid, and a method for purifying the HCV particles at a high purity in a simple manner with the use of an anti-epitope tag antibody-immobilized support.