Objective: To detect the anti-inflammatory action of magnetic targeted triptolide nano-particles on adjuvant arthritis (AA) rats and the levels of interleukin-6 (IL-6), tumor necrosis factor alpha (TNF alpha) and interleu-kin-10 (IL-10) in serum and synovial fluid, in order to investigate the possible therapeutic mechanism of magnetic targeted triptolide nano-particles on AA. Method: SD arthritis rats were used to make AA models by Fueund's complete adjuvant (FCA). A total of all model rats were randomly divided into two groups, AA control group and triptolide nano-particles group. Triptolide nano-particles group was administrated with triptolide nano-particles at 40 mu g/kg body weight intramuscularly every three days. The rats were sacrificed on the 31st day after the triptolide nano-particles administration. The production of TNF alpha, IL-6 and IL-10 in serum and synovial fluid were detected by enzyme-linked immunosorbent assay (ELISA). Results: Compared with normal control group, the levels of TNF alpha and IL-6 in serum and synovial fluid of rats in AA control group increased, but the level of IL-10 decreased(P<0.01). After the treatment of triptolide nano-particles administration, the levels of TNF alpha and IL-6 in serum and synovial fluid decreased while the level of IL-10 increased. There were significant differences in the cytokines changes between the triptolide nano-particles group and the AA control group (P<0.01). Conclusion: This study demonstrates that magnetic targeted triptolide nano-particles can possibly modulate the production of TNF alpha, IL-6 and IL-10, which may be one of the mechanisms that triptolide treats the AA and rheumatoid arthritis.