Microcalcification is one of the most common findings in breast cancer and most of cases with microcalcification only reveal non infiltrating type of cancer and better prognosis. We analysed 70 cases ofbreast cancer pathologically proved among 2,115 patients that underwent xeromammography from 1983.10.1. to1989.7.30. and studied relationship between xerographic findings and nature of infiltration in breast cancer. Theresults were as follows: 1. Among 2,115 patients a which were performed xeromammography, 70 cases were pathologically proved breast cancer and incidenced was 3.3%. 2. Incidence of breast cancer in terms of age was0.2% 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. Xeromammographic findings were classifiedmicrocalcification only, mass only, microcalcification with mass. Incidence of xerographic findings such as microcalcification only(22%) 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(67%) were more thannon-infiltrating breast cancer(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 infiltratingbreast cancer with mass(75%) was much more than non-infiltrating breast cancer(25%).