Drynariae Rhizoma (DR), an herbal medicine known to clean blood and improve its circulation, frequently appears as the main ingredient in the prescriptions for bone injuries. Currently, it is unclear how contributes pharmacologically to the reformation of bone. Therefore, we have done this study. Systematic administrations of TGFβ1 and water extract of DR diminished the polyarthritis development in rats. TGFβ administration (0.1-2 ㎍/animal) and DR (10-100 ㎍/animal), initiated 1 day before an arthritogenic dose of streptococcal cell wall fragments, virtually eliminated the joint swelling and distortion observed during the acute phase and the chronic phase of the disease. The TGFβ and DR synergistically suppressed the arthritis when the administration was begun after the acute phase of arthritis. Also, the synergistic activity between TGFβ and DR was confirmed in their suppression of arthritis in rats. Consistent with the inhibition of inflammatory cell recruitment into the synovium, TGFβ1 and DR reversed the leukocytosis associated with the chronic phase of the arthritis.