Toxoplasma gondii is an intracellular obligate parasitic protozoon that can cause zoonotic infection in humans.DNA vaccine is the emerging field of immunology and molecular biology research in recent years.In our study,pcDNA3-p30-ROP2-HSP70 nucleic acid vaccine was successfully constructed and the immune responses induced in the body were assayed.150 BALB/c mice were divided randomly into five groups,three as experimental group and were injected with pcDNA3-p30-ROP2-HSP70,pcDNA3-p30-ROP2 and pcDNA3-ROP2 respectively;two groups were injected with PBS and pcDNA3 respectively as control.All mice were vaccinated at every two weeks for three times.Blood was collected from mice of each group two weeks after third immunization to detect the level of CD4+,CD8+and cytokine.And the rest mice of each group were injected 500 RH tachyzoites of Toxoplasma gondii to detect the survival times.The result showed antibody in pcDNA3-p30-ROP2-HSP70 injected mice serum were higher in titer and recognize recombinant ROP2 antigen;After inoculation,CD4+and CD8+proliferated sharply(F=45.00,P<0.01;F=15.01,P<0.01)and CD4/CD8 ratio apparently increased in experimental groups(F=9.17,P<0.01).The levels of IL-2,IL-4,IL-12,IFN-γ and TNF in serum and culture supernatant of spleen cell and lymph cell became up-regulated,especially in serum.After infecting with toxoplasma tachyzoites,survival time of experimental group was longer comparing with control groups.Therefore,the DNA recombinant vaccine could possess strong immunogenicity and induce well immune protection.