A dearth of literature examines across-school disparities in education resources within local government agencies, particularly in Asia Pacific countries. Little is known about what leads to their inequitable distributions. In this article, we provide some answers by decomposing the inequalities of school resources. In Korea, individual schools make their own revenues from three different sources: local education government agencies (LEA), municipalities, and their parents. Following the economic literature on income inequality, we explored how much each revenue source is attributable to overall disparities. Our results reveal that the LEAs are the greatest contributor to horizontal inequality while parents are the main source of vertical inequality. These findings provide useful policy implications for better equitable distributions of public education resources.