Cynodon dactylon is used in Iranian traditional medicine as a healing agent for reducing the complications of diabetes mellitus. We proposed that Cynodon dactylon may perform its effects through moderating humoral and cellular immune responses. We aimed to determine the possible effects of hydroalcholic extract of Cynodon dactylonon humoral and cellular immune responses following the Rev1 challenge in the mouse model. 20 NMRImalemice were randomly grouped in two equal groups and immunized with Rev1[0.1 ml Rev1+0.9 PBS[. Mice in the treatment group orally received 400 mg/kg hydroalcoholic extract of Cynodon dactylon every day from the beginning of the study for 2 weeks. Blood samples were obtained from the animals 5 days after the last injection. Moreover, 48 hr before bleeding time, Rev1[0.1 ml Rev1+0.9 PBS[was injected into the left hind foot pad of mice. The levels of anti-Rev1 antibody and the specific cellular immune responses were measured by microhemagglutination test and footpad thickness, respectively. Moreover, susceptibility of macrophages respiratory burst and proliferation of immune cells were measured in order withNitroblue tetrazolium[NBT] and Microculture Tetrazolium Assay [MTT]. The concentrations of IL-1, TNFα, Il-6, and IL-10 in the serum were determined using commercially available ELISA kits. We found a significant increase in anti-Rev1 antibody levels and simultaneously a significant decrease in the level of cellular immunity[DTH] in the treatment group compared to the control group. Lymphocyte proliferation index in splenocytes was significantly increased in the treatment group. However, the level of respiratory burst in phagocytic population of splenocytes dramatically decreased in the treatment group compared to the control. A significant decrease in IL-6, TNF-α , IL-1 and increaseIl-10 serum levels were also seen in the treatment group. Cynodon dactylon extract could have an anti-inflammatory effect through downregulation of pro-inflammatory cytokines and can be considered as the moderating immune system compound.