In order to obtain the dominant immunogen of the protein encoded by p113/p126 family members of Mycoplasma ovipneumoniae. In this study, p113/p126 family recombinant proteins were prepared. We evaluated the antibody level induced by the recombinant protein of each member in the family and its binding ability with the whole bacterial protein. The binding ability of recombinant protein to whole bacterial protein was also evaluated. p113/p126 family members were rich in antigen epitopes. The recombinant proteins (rP128, rP126, and rP113) have the strongest binding ability to the serum of infected animals and belonged to the dominant immunogen. Mice immunized with recombinant protein could produce specific antibodies. The antibody produced by immunizing mice with recombinant proteins (rP113, rP109, and rP130) can effectively bind to bacterial protein. In summary, these results provided a basis for further research on the development of subunit vaccine and the establishment of serological diagnosis methods.