Abstract: Objective To explore the feasibility of chromatin-remodeling complex subunit SNF5 in the early diagnosis of breast cancer. Methods A total of 196 cases of breast cancer (0 stage 23 cases,Ⅰ stage 46 cases,Ⅱ stage 29 cases,Ⅲ stage 67 cases,Ⅳ stage 31cases,average age of 36.3) confirmed by pathological examination in Yinzhou people's Hospital Affiliated to Ningbo University from August,2010 to August,2015 were selected as study subject,and 64 cases of volunteer with health examination (average age of 37.9) in the same period were selected as control group.The peripheral blood serum SNF5 levels of two groups were detected with real-time quantitative PCR.The SNF5 levels of two groups were statistical analyzed by statistical software,and the diagnosis of SNF5 in breast cancer was analyzed by ROC curve to explore the feasibility of SNF5 in the early diagnosis of breast cancer by chromosome remodeling. Results The peripheral blood serum level of SNF5 in breast cancer patients were significantly higher than that in the control group (P<0.05),and the SNF5 level of five stage breast cancer patients were 13,15,15,16 and 23 times higher than that of control group,respectively (P<0.05).ROC curve results showed that sensitivity and specificity of SNF5 in diagnosis of in breast cancer were 82% and 93%,the area under the curve was 0.8734(95% confidence interval:0.923-0.944). Conclusion The high expression of SNF5 was commonly in breast cancer,and could be used as the biomarkers for early diagnosis of breast cancer with high sensitivity and specificity.