Objective: To investigate the anti-inflammatory effect of polysaccharide from atractylodes atractylodes(PAMK) on rheumatoid arthritis(RA) rats and its effect on Toll like receptor 4/nuclear factor kappa-B(TLR4/NF-κB) signaling pathway. Methods: RA rat model was induced by type Ⅱ collagen, after successful modeling, the rats were divided into model group, positive drug group(Tripterygium wilfordii polyglycoside tablet), PAMK low-dose and high-dose groups, normal control group was also set, with 12 rats in each group. Tripterygium wilfordii polyglycoside tablets or Atractylodes macrocephala polysaccharide were administered intragastric administration, once a day for 4 weeks. The body weight, paw swelling rate and arthritis index of rats were measured; the thymus index and spleen index were calculated; HE staining was used to observe the histopathological changes of synovial membrane of ankle joint; The levels of interleukin-1β(IL-1β), interleukin-6(IL-6) and tumor necrosis factor-α(TNF-α) in serum and synovial tissue of ankle were determined by ELISA; The expression levels of total protein TLR4, MyD88, phosphorylated NF-κB p65(Ser536) and nuclear protein NF-κB p65 in synovial tissue of ankle were detected by Western blot. Results: Compared with the normal control group, synovial hyperplasia and unclear layers were observed in the model group, body weight decreased(P<0.05), paw swelling rate, arthritis index, thymus index and spleen index increased(P<0.05), the levels of IL-1β, IL-6 and TNF-α in serum and synovial tissue of ankle, and the protein expressions of TLR4, MyD88, p-NF-κB p65 and NF-κB p65 in synovial tissue of ankle increased(P<0.05). Compared with model group, the histomathological changes of synovial of ankle joint in positive drug group and PAMK high-dose group were significantly improved, body weight increased(P<0.05), paw swelling rate, arthritis index, thymus index and spleen index decreased(P<0.05), the levels of IL-1β, IL-6 and TNF-α in serum and synovial tissue of ankle, and the protein expressions of TLR4, MyD88, p-NF-κB p65 and NF-κB p65 in synovial tissue of ankle decreased(P<0.05), however, there were no significant differences in the above indexes between PAMK low-dose group and model group(P>0.05). Conclusion PAMK can reduce the inflammatory response and improve RA, and the mechanism may be related to the inhibition of TLR4/NF-κB signaling pathway activation.