The ideal diagnostic methods in breast diseases consist of the physical examination and complementary radiologic examination. In radiologic emamination mammography is the most popular screening methods and the other simple complementary method is thermography which is efficient under the conditions of elevated skin temperature in inflammatory and malignant lesions. From Jan. 1st 1987 through Jan 30th 1988 110 pts. with complaints of mammary problems were examined by mammography and thermography at Paik hospital Inje University. The authors selected and analyzed 97 cases had been pathologically proved through the operation and the fine needle aspiration biopsy The result were as follows: 1. The most prevalent age group was 5th decade (40%) in cancer 4th decade (47%) in mammary dysplasia and followed by fibroadenoma (63%) in 4 th decade. 2. The mammographic and thermographic findings were compared between the mammary dysplasia and the infiltrating ductal cancer. In mammary dysplasia abnormal hot emissions were appeared in 9/44(17%) correlated with atypical hyperchromatic cytoplasm relates to pre-malignant group.3. We hope and expect the early detection of breast cancer through the follow-up study in pre-malignant group of mammary dysplasea.