Abstract: Objective: To analyze the important mammographic features of full-field digital mammography in infiltrative ductal carcinoma and raise the preoperative diagnosis level.Methods: Eighty-two cases confirmed by surgery and pathology were collected and retrospectively analysis in the study.All cases had been examined with full-field digital mammography before surgery.Results: Among 82 cases X-ray signs,62 cases were with round and irregular mass,48 cases with malignant calcification,which include 32 cases combining with masses,17 cases with local dissymmetrical infiltration or abnormal structures,9 cases with nipple retraction and 9 cases with local skin thickening,5 cases local skin retraction,3 cases with positive duct sign.Conclusions: Mass and malignant calcification are the most common features of infiltrative ductal carcinoma,which is important in diagnosis,and there are some unusal features,such as local dissymmetrical infiltration or abnormal structures,and the change of nipple and skin,and positive duct sign.