Abstract: Objective To investigate the expression and correlation of ZO-1,vimentin and miR-1246 in normal breast epithelial cells(MCF10A) and breast cancer cells(MCF7,MDA-MB-231),and analyze the role of miR-1246 in promoting breast cancer epithelial-mesenchymal transition(EMT). Methods The relative expression levels of miR-1246 in MCF10 A,MCF7 and MDA-MB-231 were detected by q PCR assay; the expression of ZO-1 and vimentin protein in MCF10 A,MCF7 and MDA-MB-231 were detected by WB assay. Data were analyzed using U test,t test and spearman rank correlation analysis by SPSS 16. 0. Results The expression of miR-1246 and ZO-1 in malignant breast cancer cells were significantly decreased(P < 0. 05),the expression of vimentin in malignant breast cancer cells was significantly increased(P < 0. 05). MiR-1246 was positively correlated with ZO-1 expression(r=0. 940,P < 0. 05),miR-1246 and vimentin expression were negatively correlated(r=- 0. 714,P < 0. 05). Conclusion The expression level of miR-1246 and EMT markers is correlated,so miR-1246 is suggested to play an important role in the promotion of EMT in breast cancer.