PMT was purified from sonic extracts of a serotype D strain of toxigenic Pasteurella multocida (T+Pm),with a DEAE-52 sephacel column and a sephadex G-200 column.Western blot confirmed that the toxin could specifically react with antiserum against T+Pm.Cytotoxicity on Vero cells showed that there were pathologically changes after administration of 7 ng/mL purified toxin.The toxin was emulsified with Freund’s adjuvant in equal volumes to get toxoid vaccine.Groups of healthy pigs were vaccinated four times with an interval of two weeks.The neutralization antibody titer of toxoid vaccine detected by the agar gel diffusion test was 1∶16.However,groups of inactivated bacterin and negative control didn’t produce antibodies against the toxin.All pigs were challenged intravenously with compounds of 200 μg toxin and 5 × 109 cfu HN-13 strain of T+Pm.The protection efficiency of toxoid vaccine group was 100%,and the neutralization antibody titer was 1∶32.Inactivated bacterin and negative control groups couldn’t provide any protection.The data revealed that the toxin had immunogenicity and the prepared antiserum could be used to develop diagnosis methods.