The purpose of this study is to develop dynamic population model to forecast the change in population structure on region. To achieve this, the cohort component method, the demographic balancing equation and system dynamics modeling were applied to calculate the population. The results are as follows. First, this study demonstrates the applicability of the System Dynamics as a future forecast methods. Second, this is possible to simulate demographic changes and intuitively identify the population structure on region. Also, various time-series population indices concerned on each region by 2050 were computed effectively. Finally, this study suggests that some counterplan for population reduction should be taken as soon as possible. Using this study, an estimated future population should be used as a basis for transforming the focus of regional policy objectives from a different perspective.