In recent years, breast micro-lesions such as ductal carcinoma in situ(DCIS)were detected with progress of the image diagnosis. We investigated the usefulness of vacuum-assisted biopsy(VAB)for initial biopsy of breast tumors. We analyzed 32 cases of VAB performed for breast tumors. The pathological diagnosis of the biopsy specimens was malignant lesions in 10 cases, border-line lesions in 1 and benign lesions in 21 cases. 11 cases underwent surgery and the final histopathological diagnosis was the same in 10 of them. One case histopathology varied from DCIS to invasive ductal carcinoma(IDC). It was suggested that VAB at initial biopsy was a useful biopsy method.