[Objective] The minimum immune dose and the fluctuation of antibodies of Mycoplasma bovis inactivated vaccine prepared by our research group were preliminarily studied.[Method] The prepared vaccine was injected into the leg muscles of mice at different doses of 0.1 mL/piece,0.2 mL/piece,0.3 mL/piece and 0.4 mL/piece.[Result] The minimum immune dose was 0.2 mL/piece. The antibody titer reached its peak 3 weeks after immunizing mice with the minimum dose,and then began to decline,but remained relatively stable.5 weeks later,the antibody titer showed a downward trend.[Conclusion] This study laid a foundation for the later application of mice immunized with Mycoplasma bovis inactivated vaccine in cattle.