Purpose To investigate the anti-inflammatory effect of Radix Rehmanniae Praeparata(RRP)on the footpad inflammation induced by complete Freund's adjuvant(CFA)in rats.Methods CFA 100 μL were injected subcutaneously to the Wistar rats at the pad of right hindfoots.19 days later,the rats were daily siven RRP water extract(0.625,1.250,2.500 g/kg·bw)or dexamethasone(0.5mg/ks·bw)intragastrically.The changes of body weight and foot volume were measured.The indexes of organ and blood were determined at the 29th day,the foot pad was removed,and routine paraffin section was performed.Results The model rats kept foot swelling and lymphocyte infiltrating,and the platelet number decreased.The other indexes were statistically insignificant when compared to the controls.RRP did not display any anti-inflammatory effect on the swollon foots,but thoracic gland and spleen indexes were rescued,and platelet number and creatinine content were increased by RRP administration in a dose-dependent manner.The anti-inflammation of dexamethasone was conspicuous,but the side effects were also significant.Conclusion RRP may be plays an adjunctive action in herbal recipes to treat rheumatoid arthritis.