Objective To study the expressions of Delta-like ligand 4 （DLL4） and S100A4 in breast carcinoma of differect molecular subtypes and explore its clinical significance. Methods The expressions of DLL4 and S100A4 in all molecular subtypes were tested by SP immunohistochemistry in 108 cases of breast carcinoma and 40 cases of paracancerous tissues from Taihe Hospital. The Luminal A， Lumianl B， HER-2 over-expression， and basal-like subtypes was 51， 26， 17， and 14 cases， respectively. Then the correlation of DLL4 and S100A4 expression with patients’ clinical and pathological features were analyzed. Results The positive expression rates of DLL4 and S100A4 in breast carcinoma was 67.6%（73/108）and 62.0%（67/108）respectively， which were significantly higher than those in paracancerous tissues〔22.5%（9/40） and 45.0%（18/40）〕， P＜0.05. The positive expression rates of DLL4 and S100A4 in breast carcinoma tissues of HER-2 over-expression and basal-like subtypes were significantly higher than those in breast carcinoma tissues of Luminal A and Luminal B subtypes （P＜0.05）. The expressions of DLL4 and S100A4 in breast carcinoma tissues with lymph node metastasis and without lymph node metastasis were significantly different（P＜0.05）. There was positiver elationship between the expressions of DLL4 and S100A4 in breast carcinoma tissues（rs=0.217，P＜0.01）. Conclusions DLL4 and S100A4 are highly expressed in breast carcinoma tissues of HER-2 over-expression and basal-like subtypes， and are all related with prognosis of breast carcinoma. These results suggest that they might be important factors in breast carcinogenesis and tumor development， metastasis. These proteins are indicators of metastasis and predictors for prognosis of breast carcinoma.