Samples of breast carcinoma were collected from 1l7 patients who underwent mastectomy in Korea Cancer Center Hospital from Jan. 1982 to Dec. 1984. We studied expression of the c-erbB- 2 oncoprotein and EGFR with the immunohistochemical technique. We also analyzed to clarify the relationship between expression of the c-erbB-2 oncoprotein and/or EGFR and tumor size, node metastasis, stage, histo1ogic grade, TIL, and EIC, and to evaluate the prognostic significance of c-erbB-2 oncoprotein and EGFR in breast cancer. EGFR expression rate was 37.6%(44/ ll7) and EGFR status had positive correlation with histologic grade(p<0.05), But, we did not find any other relationship with other clinicopathological prognostic factors. c-erbB-2 expression rate was 64.1%(71/1 l7). There was no relevance between c-erdB-2 expression and other prognostic factors. Higher histologic grade was poorer survival rate. EGFR positive patients had poorer prognosis than negative patients in stage I and II breast cancer(p<0.05).