Abstract: Objective To determine the roles of retionoic acid receptor β(RARβ) gene methylation in the occurrence and development of breast cancer. Methods We screened the primary human breast tumors and normal breast tissues for RARβ gene promoter methylation by methylation specify PCR(MSP), and the results were analyzed together with corresponding clinical pathological data. Results The frequency of RARβ gene methylation in 192 cases was 26% (50/192), however no RARβ gene methylation was found in normal breast tissues. RARβ methylation were associated with tumor histological type, staging and tumor size (P<0.05). Patients with lymph node metastasis, ER（-）and HER2 amplified had more RARβmethylation(P>0.05). Patients with RARβ methylation had low survival rate(P=0.268), particularly those combined with lymphatic metastasis (P=0.04). Conclusion RARβ gene promoter methylation may play an important role in the carcinogenesis and development of breast cancer. The relationship with poor differentiation, large tumor size and poor survival rate indicates that RARβ methylation could be used in the prognosis of breast cancer patients with lymphatic metastasis.