Abstract: ObjectiveTo investigate the methylation status of RAR-β2 gene and its dignostical value in sporadic breast cancer. Methods Sixty-two sporadic breast cancer tissues,15 benign breast tissues and 10 normal breast tissues were collected and subjected to methylation-specific PCR(MSP) and real-time quantitive PCR. Results Methylated rates of RAR-β2 gene promoter were observed in 50%(31/62) of breast cancer tissues, and in 20%(3/15) in benign proliferative breast tissues,but not in normal breast tissues.The prevalence of RAR-β2 gene promoter methylation in malignant was significantly higher than those in benign and normal breast tissues.No association was observed between RAR-β2 gene promoter methylation and patient's clinical-biologic characteristics including age, menostasis， but association was observed between RAR-β2 gene promoter methylation and the patients of the lymph node metastasis and clinical typing. Conclusion Our results suggest that promoter hypermethylation of RAR-β2 gene may be involved in the carcinogenesis of sporadic breast cancer.There is the correlation between promoter hypermethylation of RAR-β2 gene and the patients of the lymph node metastasis and clinical typing.