Objective: To observe the effect of moxibustion on the expressions of tumor necrosis factor-α (TNF-α) and nuclear transcription factor kappa B (NF-κB) proteins in ankle joints of rats with rheumatoid arthritis (RA), and to explore the anti-inflammatory mechanism of moxibustion in the treatment of RA.Methods: Adjuvant arthritis (AA) rat models were induced and used as rat models of RA. Rats were randomly divided into a normal group, a model group, a moxibustion group and a saline group. Rats in the normal and model groups were not treated; rats in the moxibustion group accepted treatment by moxibustion at Zusanli (ST 36) and Shenshu (BL 23) after modeling; rats in the saline group were injected with 0.15 mL saline to the bottom of the left hind paw and had no other treatments. Hematoxylin-eosin (HE) staining was used to observe the histopathological changes of rats' ankle joints under light microscope. Immunohistochemistry was used to observe the expressions of TNF-α and NF-κB in ankle joints of rats.Results: Compared with the normal group, the rats' ankle joints in the model group showed disorganization, joint surface defect, and significantly increased mean optical density (MOD) of TNF-α and NF-κB (allP<0.05). After moxibustion treatment, rats in the moxibustion group showed repaired ankle tissues, smooth joint surface without defects, decreased MOD of TNF-α and NF-κB than those in the model group (allP<0.05). Rats in the saline group had no damage to ankle joints, while TNF-α and NF-κB were significantly different from those in the model group (P<0.05).Conclusion: Moxibustion could down-regulate the expressions of NF-κB and TNF-α protein in ankle joints of RA rats, and produce an anti-inflammatory effect to promote tissue repair.