The expressions and significance of c-met oncoprotein and transforming growth factor-α (TGF-α) were studied by immunohistochemical method in 50 cases of breast cancer (BC) and 12 cases of benign lesions of breast (BL). The positive rate of c-met, TGF-α in BC was 26.0% and 25.0% respectively, in BL was 8.3% and 25.0% respectively. The positive rate of c-met oncoprotein was lower in the cases of histologic Grade Ⅰ, positive of ER and PR or CEA than that of histologic Grade Ⅲ, negative of ER and PR or CEA. The positive rate of TGF-α was lower in the cases of histologic Grade Ⅰ, negative of ER and PR or CEA than that of histologic Grade Ⅲ, positive of ER and PR or CEA. These results suggest the expression of c-met and TGF-α might be related to the carcinogenesis and development or endocrine state of BC.