The methods for the early diagnoses of breast cancer are mammography, physical examination, breast self-examination(BSE). This study was conducted to investigate the knowledge and practice of BSE by structured questionnaire which included questions on general characteristics, performance of mammography, physical examination of breast, knowledge and practice of BSE. The subjects in this study were 412 females between 20 and 69 years old who visit to the Health Care Center of College of medicine of Inje University from December 1997 to February 1998. The results were as follows: 1. Women who have gotten the regular mammography are 8.19% of these subjects and women who have gotten the regular physical examination by doctors are 4.19% of these subjects. 2. Regarding BSE, 77.4% of these subjects said that they knew BSE and 3.88% of these subjects said that they practiced BSE regularly. It was that women who knew BSE were more younger, better-educated and higher economic status(p=0.001) and lived a normal life with her husband(p=0.033). And women who practiced BSE regularly were more younger, and married(p=0.001). 3. The most common barrier to doing BSE is 'Do not see the needs/Worry unnecessarily', and the most common reasons for doing BSE is 'Early detection'. 4. The overall frequency and percentage distribution of recommended BSE step in Korea is lower than U.S.A.