A recent increase in the number of deaths and mortality rates of breast cancer occurred in Korean women. The increases shows a indirect increase in incidence of breast cancer. The number of deaths from breast cancer and the mortality rate in the future would be of use in the perspectives of breast cancer control and management in Korea. This study is to forecast cancer deaths and age-adjusted death rates in the future(2000-2015 year) by fitting modelling, assuming present trends continue. The number and mortality rate of breast cancer were fitted and estimated by simple linear regression mode. Estimated crude death rates for breast cancer per 100,000 persons were 5 person in 2000, 5.99 person in 2005, 6.98 person in 2010, and 7.79 person en 1015. The observed age-adjusted death rates per 100,000 persons were 1.08 person in 1980, 2.03 person in 1985, 2.49 person in 1990, and 3.29 person in 1995 and the estimated age-adjusted death rates per 100,000 persons were 4.01 person in 2000, 4.72 person in 2005, 5.42 person in 2010, and 6.14 person in 2015. Future estimated increase rate of the number of death is 2 times as many as the estimated rate in population-increase. Particularly noteworthy was an increasing tendency of the age-specific death rate with the ages in death, as like a mortality pattern of breast cancer in western females. These findings suggest that cohort effect might significantly contribute to the increase of the number and mortality of breast cancer in Korean women.