ABSTRACT Objective: Observe the histomorphology of intraductal carcinoma and explore the relationship between the histomorphology and age of onset. Methods: 33 cases of intraductal carcinoma were collected to evaluate the morphological characteristics by HE staining and immune-histochemical staining, and the age of onset was analyzed. Results: During 33 cases of intraductal carcinoma, there were 2 cases of papillary(6.1%), 4 cases of low papillary(12.1%), 4 cases of cribriform(12.1%), 8 cases of comedo(24.2%), 15 cases of solid(45.5%). Conclusions: There were different morphological characteristics for intraductal carcinoma. It was important to detect the occurrence of micro-invasion for intraductal carcinoma by the use of SMA and P63 in combination. There were no differences for the incidence of intraductal carcinoma of the different age groups.