Rheumatoid arthritis (RA) is a common, chronic autoimmune disease affecting 0.5-1.0% of adults worldwide, including approximately 4.5-5.0 million patients in China. The genetic etiology and pathogenesis of RA have not yet been fully elucidated. Recently, one new RA susceptibility gene (RAD51B) has been identified in Korean and European populations. In this study, we designed a two-stage case-control study to further assess the relationship of common variants in the RAD51B gene with increased risk of RA in a total of 965 RA patients and 2,511 unrelated healthy controls of Han Chinese ancestry. We successfully identified a common variant, rs911263, as being significantly associated with the disease status of RA (P = 4.8 × 10-5, OR = 0.64). In addition, this SNP was shown to be related to erosion, a clinical assessment of disease severity in RA (P = 2.89 × 10-5, OR = 0.52). These findings shed light on the role of RAD51B in the onset and severity of RA. More research in the future is needed to clarify the underlying functional link between rs911263 and the disease.