The present invention relates to a peptide capable of binding to rheumatoid arthritis autoantibodies, which is a consecutive 10-25 amino acid sequence of any one fragment of the group consisting of SEQ ID NO: 3-4, 7-13 or 16-19, wherein the peptide fragment has an epitope that binds to the rheumatoid arthritis autoantibodies. Furthermore, the peptide fragment bound to the rheumatoid arthritis autoantibodies is used for testing rheumatoid arthritis, and according to this use, the present invention provides a method for testing rheumatoid arthritis disease and a test reagent kit used for determining whether a subject to be tested suffers from rheumatoid arthritis disease.