Objectives : The present study was conducted to examine the effect of Cudraniae Tricuspidatae Radix(CTR), which is the radix part of Cudrania tricuspidata Bureau, on cytokine secretion from the joint cells and spleen cells of mice with arthritis induced by collagen and verify its efficacy against rheumatoid arthritis. Methods : Three kinds of extract were prepared from CTR through extraction with hot-water and ethanol. The levels of cytokine secreted from the cells were measured, after the mice knee joint cells were cultured with each extract. Results : The three kinds of extracts from CTR decreased the growth rate and levels of inflammatory cytokines such as IL-$1{eta}$, IL-6, and TNF-${alpha}$ from knee joint cells of mice. All of the organic-soluble fraction, such as hexane, ethyl ether, ethyl acetate, butanol, and residual water-soluble fraction decreased the levels of IL-$1{eta}$, TNF-${alpha}$, IL-6, and IL-10. Conclusion : These results suggest that CTR had some effects on rheumatitis, with fat and water-solubles in organic solvent considered as the effective element.