The purpose of this study explain the experimental effects of Guizhishaoyaozhimu-Tang (桂枝芍藥知母湯) that have clinical efficacy in rheumatoid Arthritis. Materials of present study were Guizhishaoyaozhimu-Tang freeze dried powder (GSZT), Sprague-dawley rats (300 g or so, male), various kinds of needing experimental studis. In order to study the therapeutic effects of GSZT, this Prescription (GSZT 500 mg/kg, 1,000 mg/kg) were administered per oral to the rats with the arthritis induced by Freund's complete adjuvant ($0.2m{\ell}/kg$), several experimental items were measured and compared each other ; that is body weight, rate of edema, analgesic effect by hot plate method, WBC, total protein, TNF-${\alpha}$, IL-10 and expression and localization of H&E, COX-2 staining in synovial tissues from rat with rheumatoid arthritis by immunohistochemical staining using polyclonal COX-2 antibodies. Rats were divided into four groups. Normal group was not treated with Freund's complete adjuvant and treated with DDW 1.0 $m{\ell}$, Control group was treated with Freund's complete adjuvant 0.2 $m{\ell}/kg$ and DDW 1.0 $m{\ell}$, Sample A group was treated with Freund's complete adjuvant 0.2 $m{\ell}/kg$ and GSZT (500 $mg/m{\ell}$) $1.0m{\ell}$, Sample B group was treated with Freund's complete adjuvant 0.2 $m{\ell}/kg$ and GSZT (1,000 $mg/m{\ell}$) 1.0 $m{\ell}$. 0 was day that did not start experiment, 14 was day that confirmed rheumatism induced by Freund's complete adjuvant, 28 was day that completed experiment. The following results were obtained in this study ; Sample A group was increased in body weight, escape time and paw licking time statistical significance compared with Control group, and were decreased in edema, WBC, total protein, TNF-${\alpha}$ with statistical significance compared with Control group. Sample B group was increased in escape time with statistical significance compared with Control group, and were decreased in edema, WBC, total protein with statistical significance compared with Control group. Sample A and Sample B groups were increased in IL-10 compared with Control group, and Sample B group was decreased in TNF-${\alpha}$ compared with Control group. And, Control, Sample A and Sample B groups were showed considerable reduction of positive expression in comparison to Normal group. Especially, Sample B group was most significantly reduction of positive expression than the other groups. From above results, I suggest that GuizhiShaoyaoZhimu-Tang can be used for curing rheumatoid arthritis.