Objective: To study the effects of matrine on the inflammatory response and the activities of arginase and adenosine nucleotide hydrolase in platelets of carrageenan-induced arthritis rats. Methods: The rats were randomly divided into normal group, model group, pos. drug control group(0.2 mg·kg∼(-1) dexamethasone), matrine(low, medium and high dose)(20 mg·kg∼(-1), 40 mg·kg∼(-1), 80 mg·kg∼(-1)) group. A rat model of rheumatoid arthritis was constructed by intra-articular injection of 20 μL 1% carrageenan for 7 consecutive days. From the 8 th day, the corresponding drugs were intragastrically administered every day for 21 consecutive days. On the 0 th, 7 th, 14 th, and 21 st days of administration, the thickness of each rat′s paw was measured with vernier calipers, and the arthritis index was scored; the cartilage damage was observed by HE staining; the functional phenotype of rat peripheral blood T cells was determined by flow cytometry; ELISA method to determine rat serum interferon-gamma(IFN-γ), tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), interleukin-4(IL-4) and interleukin-10(IL-10) levels; arginase activity is assessed by the concentration of urea produced by the Ehrlich reagent reaction; detection of lipid peroxidation by thiobarbituric acid reaction, determination of NTPD enzyme, 5′-nucleotidase activity and adenosine deaminase activity; the protein expression of p65 and p-IKBα/IKBα in T cells and cartilage tissue was measured by western blot. Results: The high-dose matrine group reduced the paw thickness and arthritis index of carrageenan-induced arthritis rats, improved cartilage damage, reduced the ratio of Th1 cells to Th2 cells, and reduced IFN-γ∼+, IL-1β, IL-8 and TNF-α content, increase IL-4 and IL-10 content, reduce arginase activity, TBARS production and ATP/ADP/AMP hydrolysis, increase adenosine deaminase activity, reduce P65 and p-IKB/IKB expression. Conclusion: Matrine can inhibit arthritis, which may be related to its ability to inhibit inflammation, maintain Th1/Th2 balance, reduce arginase and adenosine nucleotide hydrolase activities, and inhibit NF-κB signal transduction.