Objective To investigate the expression of ER and PR in hyperplasia of mammary glands and breast cancer. Methods The expression of ER and PR in 68 hyperplasia of mammary glands cases and 168 breast cancer cases were quantified by immunohistochemical method. Results The expression of ER in breast cancer(30%) was significantly higher than that in hyperplasia of mammary glands(10 %)(P ＜0.05) and there was no significant difference in PR between them. The expression of ER in postmenopausal breast cancer was significantly higher than that in postmenopausal hyperplasia of mammary glands (P ＜0.05) and there was no significant difference in ER between two premenopausal groups. The expression of PR in invasive lobular carcinoma was significantly higher than that in invasive ductal carcinoma and other types (P=0.005).Conclusion The expression of ER and PR may identify the characteristics of patholobiology in breast disease.