To explain the mechanism of GRHP against rheumatoid arthritis (RA).RA rats’ model was constructed by collagen-induced arthritis (CIA) method and wind-cold-dampness stimulant condition,and screened by arthralgia index (AI) more than four.RA rats were classified to four groups such as model and three dose-ratio groups of GRHP except for normal group.Blood serum cytokine level of each rat was determined by ELISA approach,for example,rheumatoid factor (RF),C-reactive protein (CRP),thromboxane B2 (TXB2),prostaglandin E2 (PGE2) and prostacycline (PGI2).Whole blood COX-1 and COX-2 mRNA expression of each rats was determined by Real time quantitative PCR approach.As was shown in results,AI and blood serum cytokine level such as RF,CRP,PGE2 and PGI2 were markedly decreased,whole blood COX-2 mRNA expression reduced,body weight increased in the rats of dose-ratio groups by comparing with model group twenty-one day after intragastric administration.Therefore,GRHP has anti-inflammatory and anti-rheumatoid arthritis effects by downregulating COX-2 mRNA expression and decreasing proinflammatory factor level such as PGE2,PGI2,et al.