Since 1962, the population growth control has been one of the most important aims in the 5-Year So-cioeconomic Development Plans of Korea. The annual population growth rate has dropped to tess than 1 percent in 1990 from about 3 percents in 1960s, and projected to reach to $ulcorner$0$urcorner$ percent in 2021. From 2021, Korean population will decrease and the age structure will be distorted because birth rate will drop suddenly and continuously. Thus, we can consider $ulcorner$0$urcorner$ growth population for minimizing the prob- lems on the decreasing population. To discuss the problems caused from the changes of population size and age- sex composition, we projected three kinds of population including two kinds of $ulcorner$0$urcorner$ growth population under different as- sumptions. The first is the population which extended the projection of National Statistical Office up to 2090. Because the TFR is assumed and fixed as low as 1.63 after 1990, the population growth rate will be under $ulcorner$0$urcorner$ in 2021 and drop by about 1 percent every year from around 2050. This population trend results to old age population : 38.1 of old- age dependency ratio and 46.5 years of median age. The second is the population which the size in 2021 projected by the NOS continues after 2021. To change over from the decreasing population after 2021 to the $ulcorner$0$urcorner$ growth one, the TFR should be in-creased up to over 3.0 in 2040-2050, which fertility level would be too high to be accepted. The third is the population which approaches to the $ulcorner$0$urcorner$ growth population under the assumptions that the TFR increases from 1.63 to 2.1 in the period of 2010-2030 and then the same level continues. Although the maximum population size reaches 51, 503 thousand persons, the population will approach to the stationary population with about 42.4 million persons around 2090. In this projected population there is no more serious problems on population composition, on the rapid decrease of population, and on the increase TFR level. When the $ulcorner$0$urcorner$ growth population continues the problems of over population caused by the populationincrease wou]d be minimized, and the problems of unusual age composition resulted from the popula-tion decrease would not be found any more. Furthermore, when the changes of population size and composition is continuing slowly, the factors of population would effect moderately to socioeconomic development and help social changes. Therefore, with the attention of the present population changes, we should adapt new and detailde population policy which is able to get the $ulcorner$0$urcorner$ growth population.