Objectives : The purpose of this study is to prove the effect of Gamikyejakjimo-tang (ji$ar{a}$w$grave{e}$igu$grave{i}$sh$acute{a}$ozh$ar{i}$m-t$ar{a}$ng, GK) on rheumatoid arthritis. Methods : We checked viability and measured production of IL-$1{eta}$, IL-6, IL-17, TNF-${alpha}$ in RAW 264.7 cell after treat by GK. Then we measured rheumatoid arthritis index score of DBA/1 mice with rheumatoid arthritis induced by CIA after GK oral administration, checked IL-$1{eta}$, IL-6, IL-17, TNF-${alpha}$ and hs-CRP tests in serum. Also we were observed mRNA expression of IL-$1{eta}$, IL-6, IL-17 and TNF-${alpha}$ in spleen by RT-PCR. Results : GK showed cell viability of 100% or higher in all concentration in RAW 264.7 cells. GK inhibited LPS-induced productions of rheumatoid arthritis mediators cytokine in RAW 264.7cells. GK treated group showed improvement from rheumatoid arthritis at decreased the index score. Also, GK treated group decreased level in serum of IL-1b, IL-6, IL-17, TNF-a and hs-CRP tests by 31%, 35%, 20%, 57% and 58% respectively. Finally, GK treated group showed decrease expression of IL-$1{eta}$, IL-6, IL-17 and TNF-${alpha}$ mRNA in spleen by 46%, 51%, 25% and 42% respectively. Conclusions : In this study, in-vitro and in-vivo results observed rheumatoid arthritis factors cytokine of IL-$1{eta}$, IL-6, IL-17 and TNF-${alpha}$ decrease in RAW 264.7 cells, serum, mRNA expression. Also, GK showed decrease of inflammation figure in hs-CRP tests depending on effect of rheumatoid arthritis. Thus, these results can used as a effective drug of GK for rheumatoid arthritis.