Microcalcification in one of the most common findings in breast cancer and most of cases with micrcalcification only reveal non infiltrating type of cancer and better prognosis. We analysed 70 cases of breast cancer pathologically proved among 2,115 patients that underwent xeromammography from 1983.10.1. to 1989.7.30. and studied relationship between xerographic findings and nature of infiltration in breast cancer. The results were as follows: 1. Among 2,115 patients which were performed xeromammography, 70 cases were pathologically proved breast cancer and incidence was 3.3%. 2. Incidence of breast cancer in terms of age was 0.2% in third decade. 1.2% in fourth decade, 4.4% in fifth decade, 14.3% in sixth decade, 15% over seventh decade. Of total 70 patients, 51 cases were included over fifth decade. 3. Xeromammongrphic findings were classified mocrocalcification only, mass only, microcalcification with mass. Incidence of xerographic findings such as microcalcification only(2 %) was less than that of mass density(78%). 4. In 16 cases of microcalcification only, Incidence below 50 years(75%) were more than that over 50(25%). 5. Infiltrating breast cancers(33%) and number of non-infiltrating breast cancer with xerographic finding of microcalcification only(56%) was no more than that of infiltrating breast cancer(44%) but number of infiltrating breast cancer with mass(75%) was much more than non-infiltrating breast cancer(25%)