Objectives The purpose of this study was to investigate the antiallergic and antioxidative effects of Chaenomeles Sinensis (CS). Methods CS pretreatments inhibited anti-DNP IgE in RBL-2H3 mast cells for an hour. we measured cell viability, $eta$-hexosaminidase release, IL-4, TNF-$alpha$ secretion, and IL-4, TNF-$alpha$ mRNA expression CS pretreatments inhibited DNP-HSA($10;{mu}g/ml$) for ten minutes, we measured Dicholrodihydrofluorescein(DCF) and DPPH radical-scavenging activity in 0.5 mM 1,1-diphenyl-2-picrydrazyl(DPPH) radical solution, 0.1ml, 99% ethanol 0.8ml, and CS 0.1 ml mixed solution. Results 0, 1, 2, 3, 4, 5 mg/ml CS treatments were not affect on cell viability and inhibited b-hexosaminidase release, IL-4, TNF-$alpha$ secretion, CS treatments also decreased IL-4, TNF-$alpha$ mRNA expression in RBL-2H3 cells. CS treatments inhibited reactive oxygen species(ROS) and DPPH radical-scavenging activity. Conclusions These results suggest that CS may be useful for the prevention or treatment of allergic disease.