Abstract: The expression of ER,PR and DAKO-M1 in 106 breast carcinomas were examined by both affinitive histochemical and ABC technique.The positive rates of ER,PR and DAKO-M1 were 83%,81.1% and 80.2% respectively.76 cases of the 88 ER-positive breast carcinomas were PR-positive and 10 cases of 18 ER-positive ones were PR-positive.We found that the expression of ER were in accordance with PR(p<0.05) in 79.2% of the breast carcinomas.As to the expression of DAKO-M1,84 were M1-positive in 98 ER-and/or PR-positive breast carcinomas,and 7 were M1-negative in 8 ER-and PR-negative ones.There for the expression of ER and/or PR were in accordance with M1((p<0.05).The positive rates of ER,PR,and DAKO-M1,whose expression showed remarkable significance((p<0.Ol～0.001),reduced with the increase of hitological differentiation.Thus the level of ER,PR and DAKO-M1 can serve as a reference and may be beneficial to the treatment of patients.