An oriental herbal combination (BDX-1) was isolated from Achyranthes bidentata and Atractylodes japonica. We previously tested the clinical effectiveness of BDX-1 in rheumatoid arthritis (RA) patients and found that it has a beneficial therapeutic effect. Here, we provide experimental evidence for the effectiveness of BDX-1 on RA in murine models. The oral administration of BDX-1 was found to markedly inhibit collagen-induced arthritis, adjuvant-induced arthritis, and zymosan-induced inflammation. It also inhibited carrageenan-induced acute edema and acetic acid-induced writhing response. In addition, the biological activity of BDX-1 was found to be strongly increased by fermentation. Our results suggest that BDX-1 could be useful for the treatment of rheumatoid arthritis.