Objective To compare the sensitivity and specificity of outer membrane protein (OMP) and lipopolysaccharide (LPS) of Pasteuralla pneumotropica used as serological diagnostic antigens to detect Pasteuralla pneumotropica.Methods LPS,OMP and whole cell(WC) were used as ELISA and Western Blot antigens to characterize the IgG antibody of mice with natural and experimental infection of Pasteuralla pneumotropica, meanwhile the cross_reaction of three antigens to common laboratory animal pathogens was also evaluated by ELISA and Western Blot methods.Results Three antigens were tested with sera from experimentally and naturally infected mice in different ages via ELISA.LPS showed the greatest antibody ratio,WC antigen showed lower,and OMP lowest.In naturally infected mice colony,the antibody ratio of LPS in 4_week age mice was 80%,while that of whole cell antigen and OMP only 25% and 20% respectively,showing that LPS was the most sensitive one.Three kinds of antigens were also tested with sera from uninfected mice and antisera of common laboratory pathogens via ELISA and Western Blot.WC antigen had a high A value in ELISA,but it was proved to be unspecific using Western Blot.LPS was the most specific antigen,and OMP second.Conclusion The mixed species specific and typical specific OMP and LPS in ELISA to detect latent infection of P.pneumotropica in laboratory animals have more specific and sensitive than WC antigen.