Abstract: The present invention relates to a peptide having the amino acid sequence: Lys Arg Ser Thr Asn, Arg Arg Tyr Lys Glu Lys Glu Lys or Ala Ile Ile Pro Asp Arg Glu Val Leu Tyr and which peptide is capable of specifically binding to the antibody which is specific to the non-A, non-B hepatitis associated antigen. The peptide can be used as an anti-HCV antibody assay reagent with high sensitivity.