Abstract: With PCR and biochemical reaction test, sixty-six strains of Pasteurella multocida(Pm) was isolated from the lung tissues of pneumonic swine or nasal swabs of swine suffering progressive atrophic rhinitis(PAR) swine. Their medicine sensitivity was then studied. PCR assay was used to type these Pm isolates, as well as test the toxA gene. Guinea pig skin test and mouse lethal test were used to study the toxigenic pasteurella multocida (T⁺Pm). The results showed that all PCR positive strains were coincident with the biochemical reaction criteria of Pm. PCR typing assay indicated that forty-six strains were serogroup D, eighteen strains were serogroup A, one strain was serogroup B and one strain was untypable. Eight strains were identified as T⁺Pm by PCR method. Guinea pig skin test and mouse lethal test also confirmed that the eight isolates were T+Pm. All the eight T⁺Pm strains were serogroup D, and were isolated from the swines suffering severe PAR.