Abstract: 50 patients with active rheumatoid arthritis who have no improvement after twomonths' treatment with NSAIDs were divided into two groups randomly. One group accepted the treatment of MPS plus NSAID.While another group accepted the treatment of MTX plus NSAID. The clinical result and the effect on patient's immune fuction had been evaluated after six months' treatment.Then the treating programs in the two groups were exachanged and continued for another six months. Once again the result and the effect were appraised . At the same time, the adverse reactions of MPS and MTX were observed. The results of the oneyear's study showed that the total effective rate was 48% in the group of MPS plus NSAID, but 60% in the group of MTX plus NSAID. Howere there was no statistical significant difference between the two groups. The observation of the side effects showed that it was 3.8% in the MPS group,but 32% in the other.The patients' CD₃ and CD₄ Tlymphocytes in peripheral blood decreased after the use of MTX, denoting that the immune function was suppressed. But by using MPS, both CD₃ and CD₄ can be regulated in two ways.This study shows that MPS can be used in the treatment of rheumatoid arthritis.

Key words: Mycobacterial polysaccharides(MPS), rheumatoid arthritis, methotrexate(MTX)