It is an object of the present invention to provide a method and kit for diagnosing osteoarthritis which involves genetic diagnosis or hemodiagnosis. The present invention provides a method for diagnosing a genetic susceptibility of a subject to osteoarthritis, which comprises detecting at least one polymorphism selected from polymorphisms existing in a gene (Dual Intracellular on Willebrand factor A gene； DIVA gene), encoding the amino acid sequence of SEQ ID NO: 2 or an amino acid sequence substantially homologous thereto, in a DNA-containing sample collected from the subject, wherein an allele frequency of one of alleles is higher in arbitrary osteoarthritis group than in arbitrary non-osteoarthritis group.
