Objective: Our previous study has showed that (DNMT3B is the predominant form of DNMT3B in non-small cell lung cancer (NSCLC). In this study, we aimed to explore the expression patterns of the (DNMT3B variants in breast cancer and to identify whether the pattern was similar to that in NSCLC or not and its clinical significance.Methods: Expression of seven (DNMT3B variants in 59 breast cancer and the corresponding normal tissue was measured using RT-PCR. The correlations between the expressions of (DNMT3B variants and the clinical parameters including ER/PR status, clincopathologic feature and survivals were analyzed.Results: There were significant differences in the expression ratios of (DNMT3B1-7 variants between breast cancer tissues and normal tissues (P