This invention provides a serotyping method, a serotyping PCR kit, and a primer pair for Mannhemia haemolitica, enabling simple and rapid serotyping of the species. [Solution] For the 12 serotypes of Mannhemia haemolitica (A1, A2, A5, A6, A7, A8, A9, A12, A13, A14, A16, A17), 11 specific
capsule-coding genes are targeted, with serotypes A14 and A16 having homologous
capsule-coding genes.