Objective:To investigate the efficacy and mechanism of classical arthralgia decoctions,we parallelly compared the difference among Wutou,Baihu Guizhi and Guizhi Shaoyao Zhimu decoction by the idea of syndrome differentiation through formula effect assessment,and provide experimental basis for "treating the same disease with different methods".Method:The model were used classic adjuvant arthritis rats.The 30 day after modeling,the standard decoctions were given for 15 days.We observed the rat paw swelling at the various time points after administration.The rats were sacrificed at the 45 day,we observed the pathology of rat ankles and collected serum to detect serum factors (IL-6,ACPA and RF) by ELISA.Result:Compared with the model group,Wutou decoction,Baihu Guizhi decoction and Guizhi Shaoyao Zhimu decoction groups paw swelling,pathology and serum factors (IL-6,RF and ACPA) were obviously decreased (P<0.05).Although there were no significant difference among the three decoctions,but Wutou decoction was less obvious and Baihu Guizhi was the best.Conclusion:Wutou decoction,Baihu Guizhi decoction and Guizhi Shaoyao Zhimu decoction have good effects on RA.Comparison of the three classic recipes,the order of efficacy is Baihu Guizhi,Guizhi Shaoyao Zhimu and Wutou.It reveals the effect of this difference may be related to the cold-heat nature of Chinese medicine.