ABSTRACT
By reviewing documents and learning from the Dai medicine teachers, the papertried to show the theory and methods of Dai medicine on diagnosing and treating Rheumatoid arthritis (RA). Dai medicine took a note that RA was caused by the unbalance of the interal Sita and affected by the external Paya Longgananhuang. Those pathogeny can make the partial joint and muscle's function abnormal, which resulted in the RA. RA can be separated into three types which are Longmengshahoufeixiang. They could be treated by boththe internal and external treatments. The etiology and pathogenesis of RA and its diagnosis and treatment methods of traditional Dai medicine were profound, unique and useful. It`s worth of clinical application and further researches.