Abstract: Mycoplasma synoviae（MS） infection disease is an acute or chronic disease of chickens and turkeys which is caused by Mycoplasma synoviae. To control the Mycoplasma synoviae infection， in this study， MS WVU1853 strain with Montanide ISA 206 VG adjuvant were used to prepare inactivated vaccine. Inactivated MS vaccine could activate the chicken bone marrow derived dendritic cells（DCs） in vitro， DCs can uptake inactivated MS vaccine and present antigen to T lymphocytes and promote the proliferation of T lymphocytes， flow cytometry method was used to detect the subsets of proliferous T lymphocytes， the proliferation ratio of CD4+ T cells were higher than that of CD8+ T cells. SPF chickens treated with high dose of inactivated MS vaccine （1010 CFU·mL-1） induced significantly higher impression of IFN\|γ than the control group（P<0.05）. CD4+ T cells mainly differentiated into Th1 type cells and released IFN\|γ to promote CTL cells playing a role in killing. All of these proved that inactivated MS vaccine could induce cellular immune response effectively in immunized chickens. 7\|day\|old chickens were treated with inactivated MS vaccine， single immunization could produce complete protection of the attack with Mycoplasma synoviae. The safety test of the vaccine showed that the vaccine was safe and effective for chickens.

Key words: Mycoplasma synoviae, inactivated vaccine, dendritic cells, cellular immunity, immune protection