The inhibitory effects of 25 polyphenols against in vitro allergic reactions were compared using biochemical and cell assays. Three polyphenols including curcumin, gallic acid, and quercetin suppressed the release of $eta$-hexosaminidase from ionophore A23187-stimulated RBL-2H3 cells more effectively (>50% inhibition at $100{mu}M$ concentration). They were found to have potencies in suppressing the release of histamine not only from ionophore A23187-, but also from immunoglobulin E (IgE)-stimulated RBL-2H3 cells. Moreover, such suppressive effects of the three polyphenols were also observed in A23187 plus PMA-costimulated rat peritoneal mast cells. The extent of inhibition were quantified as the respective polyphenol concentration that inhibit 50% ($IC_{50}$) of $eta$-hexosaminidase or histamine release, showing an inhibition tendency with decreasing order of curcumin>gallic acid>quercetin. Down-regulation of $Ca^{2+}$ influx was suggested as the cause of the inhibition of $eta$-hexosaminidase and histamine releases in these cells. The immune process inhibition was confirmed by the observed reduction in the gene expressions and release of pro-inflammatory cytokine tumor necrosis factor (TNF)-$alpha$, interleukin (IL)-$1eta$, and IL-4, due probably to antioxidant activity of the polyphenols. These findings illustrate that curcumin, gallic acid, and quercetin may be beneficial against allergic inflammatory diseases.