Objectives The purpose of this study is to investigate the effects of Gardenia jasminoides for. grandiflora extracts' (GAJ) anti-inflammatory effect on RBL-2H3 mast cells and OVA/alum-sensitized mice. Methods In this study, IL-4 and IL-13 production was measured via ELISA analysis, and mRNA expressions of GM-CSF, IL-4, IL-5, $TNF-{\alpha}$, IL-6 were analyzed by real-time PCR. In addition, MAPKs and $NF-{\kappa}B$ p65 transcription factors were examined using western blotting, and ELISA was used to understand IgE, IL-4, and IL-13 production in ovalbumin-allergic mice in in vitro study. Results As a result of this study, 1. GAJ were observed to suppress the mRNA expression of GM-CSF, IL-4, IL-13, IL-5, $TNF-{\alpha}$, IL-6 in comparison to PMA 50 ng/ml, ionomycin $0.5{\mu}M$ (PI) control group. 2. GAJ also inhibited the IL-4, IL-13 production in comparison to PI control group. 3. Western blot analysis showed decrease on the expression of mast-cell-specific transcription factors, including MAKPs (ERK, JNK, p38) and $NF-{\kappa}B$ p65. 4. Orally-administered GAJ group in OVA/alum induced Balb/c mice showed decreased level of OVA-specific IgE in the serum. This group also has shown decreased the level of IL-4, IL-13 in the splenocyte culture supernatant. Conclusions Obtained results suggest that GAJ may regulate the allergic inflammation by transcription factors MAKPs (ERK, JNK, p38) and $NF-{\kappa}B$ p65 causing inhibition of Th2 cytokines in mast cells and OVA/alum-sensitized mice.