Abstract: The present invention provides a novel method for classifying antibodies. Specifically, the present invention provides, for a first immunological entity and a second immunological entity, a method for classifying whether a binding epitope is the same or different, and a method for performing clustering based on the classification, the methods including: identifying an array of immunological entities such as antibodies as several portions (for example, a framework region and three CDRs); in order to define a storage region, using the array as a three-dimensional structure model; introducing an index of similarity such as structure and/or array characteristic amounts into an evaluation function for evaluating the similarity or dissimilarity of two immunological entities; and analogizing the similarity of an epitope on the basis of the similarity of an antibody.