To evaluate effect of CRSST on inhibiting the occurrence of arthritis, we performed the experiments including production of inflammatory cytokine and immunoglobin in collagen induced arthritis model. The results were obtained as follows. CRSST extract shows any cytotoxicity effect on mouse lung fibroblast cells at dose of 400 ㎍/㎖. CRSST group shows inhibitory effect on arthritis incidence than control group for six weeks. Arthritis index of CRSST group reduces from 4 weeks (75±17.4%) to 6 weeks (33.3±10.0%) compared with control group. In CRSST group, production of cytokines which shows suppressive effect on inflammation (IL-4, IL-10 ) are increased and which promotes inflammation (TNF-α, INF-γ) are decreased in blood. In CRSST group, production of immunogloblin (IgG2b, IgG3 and IgM) is reduced compared with control group, and rate of CD4+ and CD3+ T cell is lower in joint and higher in lymph node compared with control group. From above results it could be accepted that CRSST shows anti-arthritis effect via immune system especially through the controlling the inflammatory cytokines and immunoglobins. CRSST could be usefully applied for the prevention and treatment of RA. And also is expected to be clinically helpful on the treatment of RA through modification.