Aging population combined with the diminishing number of children is a critical social problem of Japan. This problem is especially serious in rural regions which population density is low. We propose a new method to project the population of less densely populated region using 0.5-km squared grid system data. And, we evaluate the result of applying this method to Yamagata Prefecture. There are three key concepts in this research. First is the spatial moving average cohort change rate which enables us to get suitable cohort change rate. Second is the integrated grid system data that is derived from the analysis of seeking appropriate size of grid system data. And the third is error estimation of population projection which enables us to have interval projection with stochastic basis.
