Objective :To investigate expression of E-Cadherin(E-CD) in breast cancer cells and its relationship to clinical and pathological character and to the incidence of tumor cells shed from the surgical field. In an attempt to study more deeply about the mechanisms of invasion and metastasis of breast cancer and give some reference to the diagnosis and treatment of breast cancer. Methods: The expressions of breast carcinoma cells were studied using immunohistochemical methods(ABC methods).Semi-quantitative methods were used to judge the results. For statistical analysis, Chi-square test and the exact probability in 2 ?2 table were used. Results : E-CD positive was located on cell membranes and cytoplasms, mainly on membranes, showing different intensity of brown pellet. Of 52 cases, twenty nine percent retained normal E-CD expression, seventy one percent have reduced or even none expression. E-CD expression has significant correlation with histological grade. Reduced and lost expression rate in Grade 1(36.4%,4/11) were much lower than grade 2(77.8%,28/36)and grade 3(75%,6/8) (p