Abstract: Objective: To investigate the clinicopathological characteristics and prognosis of invasive micropapillary carcinoma (IMPC) of the breast. Methods:Data of65IMPC cases obtained from the Fourth Hospital of Hebei Medical University between Janu -ary 2009and December 2011 were retrospectively analyzed. The expression of epithelial membrane antigen (EMA) was evaluated us-ing immunohistochemistry (IHC) to detect the micropapillary component in the tumor. The patients were divided into 4 groups based on the percentage of micropapillary component: ≤ 10%,11 %-30%,31%-50%, and >50%. Expressions of estrogen receptor (ER), pro gesterone receptor (PR), and HER-2 were analyzed by IHC. Kaplan- Meier method, Log rank test, and multivariate Cox proportional hazard model were used to determine the factors affecting post-treatment survival. Results: Of the 65cases, 12were simple IMPC, 46 were IMPC with invasive ductal carcinoma, and 7 were other invasive carcinoma cases. The ≤ 10%,11 %-30%,31%-50%, and >50% micropapillary component groups comprised7.69% (5/65), 44.62% (29/65), 26.15% (17/65), and 21.54% (14/65) of the total cases, re -spectively. Statistically significant differences were found in the four groups (P<0.01). IHC results showed that the positive rates of ER, PR, and HER- 2 in the IMPC tissues were 76.92% (50/65), 67.69% (44/65), and 24.62% (16/65), respectively. Statistical differences ex-isted among the groups (P<0.05). Kaplan-Meier method indicated that positive rate of lymph node metastasis, the proportion of IMPC, vascular invasion, and the expression of ER, PR, and HER- 2 significantly affect survival time of IMPC cases (P<0.05). Conclusion: Positive rate of nodal metastasis, the proportion of IMPC, vascular invasion, and the expression of ER, PR, and HER-2 are correlated with the prognosis of IMPC.