Early detection of breast cancer is crucial to improve the therapeutic effect and to increase the survival rate. However, it is difficult because breast cancer in early stage was usually occult, impalpable, and could not be detected by laboratory test. This study was designed to compare the effectiveness of three methods for diagnosis of non-palpable breast cancer.Twenty-four patients with impalpable breast mass suggested by computer-aided stereotactic mammography were performed with three kinds of methods, including fine-needle aspiration cytology (FNAC), large-core needle biopsy (LCNB), and frozen section biopsy (FSB) with focus staining. The results were compared with postoperative pathology.Compared with postoperative pathology results, the diagnostic consistent rates of FNAC, LCNB and FSB with staining focus were 75%, 92%, and 100%, respectively (P< 0.05).Frozen section with focus staining guided by computer-aided stereotactic mammography was the effective diagnostic technique for non-palpable breast cancer.