Objective To evaluate the applied value of CT in breast lesions.Methods Imaging data of 120 patients with normal breast were reviewed retrospectively in 4 groups of different age(15～25,26～35,36～50 and 51～80),and imaging data of 49 patients with breast lesions biopsy-proved were also analysed.Of 49 breast masses,31 were malignant tumor,18 were benign lesion.All the patients underwent CT scan with supine position whole thoracic region.Results The CT imaging features of normal breast in different age groups were different.65% of normal people had small sporadic axillary lymph nodes.Breast cancer usually showed hillslike and benign tumor showed round oroval-shap.The signs of spiculated lesion,deformed adipose space and thicken of local skin were statistical difference between benign and malignant lesions(P0.05).The metastatic axillary lymph nodes usually showed as the significant enlarged nodes with indefinite margin or multiple small nodes.Conclusion CT scan is valuable in detecting breast disease and differential diagnosis,and also can offer the informations on tumor staging and treatment.