Objective To analyze the differences of immune responses against Mycobacterium tu-berculosis antigens induced in two different nonhuman primates and to provide rationales for the selection of suitable animal models for vaccine efficacy evaluation.Methods Expression of functional surface markers including CD69 and HLA-DR, the activation markers on CD4+and CD8+T cells from in rhesus macaques and cynomolgus monkeys were measured by flow cytometry analysis.PBMCs were isolated from rhesus ma-caques and cynomolgus monkeys with Mycobacterium tuberculosis infection and stimulated with PPD and pep-tide pools ( ESAT-6/CFP-10) .Enzyme-linked imunospot ( ELISPOT) assay was performed to detect IFN-γproducing lymphocytes.Results The CD4+and CD8+T cells isolated from rhesus macaques without Myco-bacterium tuberculosis infection expressed higher levels of CD69 and HLA-DR than those from healthy cyno-molgus monkeys (P<0.01).The numbers of IFN-γspot forming cells/106 PBMCs in rhesus macaques with Mycobacterium tuberculosis infection for 10 and 11 months were respectively 3 and 3.5 times higher than that of cynomolgus monkeys upon after the stimulation of PBMCs with PPD.The levels of IFN-γproduction by the cells from rhesus macaque group were also higher than those from cynomolgus monkey group upon after the stimulation of PBMCs with ESAT-6 or CFP-10 peptide pools.Conclusion More IFN-γproducing cells were induced in rhesus macaques than that in cynimolgus monkeys after stimulation with Mycobacterium tu-berculosis antigens.Therefore, the rhesus macaques might be a better animal model for evaluating immune responses induced by Mycobacterium tuberculosis vaccines.