This study shows trends and age-sex patterns of mortality in Korea, based on adjusted death registration data during 1956∼1980. Description on the data-the types of errors and their methods of adjustment-are presented elsewhere (Kim, 1986). Crude death rates have declined in 20 years to 7.0 in 1976∼1980, almost half the level of 13.0 in 1956∼1960. Mortality of females declined faster than males, especially at older ages. Substantial differences in provincial mortality are observed based on the expectation of life at birth. The difference between the highest and the lowest provinces is 9.2 years for males and 8.3 years for females during 1976∼1980. This study presents two interesting features of age-sex patterns of mortality in Korea. One feature is higher female mortality than males during childhood periods. However, infant mortality is higher for males than for females throughout the period, though the difference is much smaller than is expected from various model life tables. Another feature is the rapid rise in mortality for males after age 40. This pattern is found to be existed throughout the period 1956∼1980. Further studies are recommended to establish its causal linkage to traditional sex role (as main bread winner) and health behavior (smoking and drinking) of males and recent rapid industrialization in Korea.