The pr otein and antigen mapping of 11 isolates of Pasteurlla pn eumotropica from different of breed facilities were analyzed. The results of 5-2 0% and 10-20% SDS-PAGE showed that there are 25-30 protein bands between 14.4-97 .4kD. The 12% SDS-PAGE revealed the major protein bands evident at approximately 31,34 and 42.7kDa in all isolates tested. 6 of which have the same mapping comp are with the reference strain, 5 are lack of 40kDa band. Western bolt analyses i ndicated the major antigen at approximately 17 and 31kDa in all isolates tested (the reference stain included), with the antisera of P.pneumotropica. Same test with mice sera of the naturally infected by P.pneumotropica, the major antigen at approximately 17kDa. 5 isolates tested lacked of 40kDa protein showed 31kDa b ands, and the others revealed 20 and 28kDa bands. This study demonstrated that t he different of the isolates of P.pneumotropica have the similar protein banding patterns. most of them are at the approximately 31, 34 and 42.7kDa. The major antigen are 17 and 31kD protein. Two types of P.pneumotropica could be classif ied according to 40kDa protein and 20, 28kDa antigen. The study could be the bas ic for purifying the diagnostic antigen and monitoring the P.pneumotropica with SDS-PAGE and Western blot.