This paper deals with the changes of aged dependency ratio across the 211 administrative districtions of South Korea between 1995 to 2011. The results show the dynamics of empirical distribution and Theil-L inequality indices for aged dependency ratio. The paper also analyzes the cause of aging inequality among regions. We find that the increase of aging inequality in regional level was mainly due to population mobility before 2005. However, the regional aging inequality is decreasing recently.