Objective To assess the effect and safety of periodontal therapy in relieving the symptoms and clinical signs of rheumatoid arthritis（RA）. Methods The electronic search was conducted in Medline（OVID, 1950—2010 Sep）, EMBASE（1984—2010 Sep）, CENTRAL（2010, Issue 3），CBM（1978—2010 Sep） and the Chinese journals on stomatology were hand-searched. Clinical randomized controlled trials as well as clinical controlled trials were selected regarding the targeted issue. Two investigators evaluated the reporting quality and risk of bias of those included trials in accordance with CONSORT statement and Cochrane risk of bias assessment tools, and collected data of included studies in duplicate. Revman 5.0.23 was applied for Meta-analysis. Results Four trials met the inclusion criteria and a total of 150 patients were enrolled in the trials, one had low risk of bias and others had moderate risk of bias. Metaanalysis showed that pure periodontal therapy could not decrease disease activity score in 28 joints（DAS28）（P=0.06）, and there was no statistically significant difference between periodontal therapy with anti-tumor necrosis factor-α（TNF- α） medication and pure anti-TNF-α medication（P=0.24）. But the subgroup analysis showed that a significantly decreased DAS28 was achieved by periodontal therapy（P=0.03）, and the interventions provided a remarkable effect on alleviating clinical signs and erythrocyte sedimentation rate of RA（P
