In previous report, Seungmagalgeun-tang (SGT) could exert its anti-inflammatory actions in the BV-2 microglial cells. However, study on the anti-inflammatory effect of SGT in mast cells has not been identified. Therefore, we examined on the anti-inflammatory effect of SGT on the phorbol 12-myristate 13-acetate (PMA) and calcium ionophore A23187-induced rat basophilic leukemia (RBL-2H3) cells. SGT inhibited the release of ${eta}$-hexosaminidase and secretion and expression of pro-inflammatory cytokines such as tumor necrosis factor (TNF)-${alpha}$ and interleukin (IL)-4 on RBL-2H3 cells, without affecting cell viability. The protein expression level of nuclear factor (NF)-${kappa}B$ (p65) was decreased in the nucleus by SGT. In addition, SGT suppressed the degradation of inhibitory protein $I{kappa}B-{alpha}$ protein, the activation of p38 mitogen-activated protein kinase (MAPK), and the expressions of cyclooxygenase (COX)-2 mRNA and protein level in RBL-2H3 cells. These results suggest that SGT could be involved anti-allergic effect by control of NF-${kappa}B$ (p65) translocation into the nucleus through inhibition of $I{kappa}B-{alpha}$ degradation and suppression of COX-2 expression.