This paper seeks to provide a conceptual framework for understanding the topic of public aid to Christian schools in a Reformed Christian perspective. To do so, I need to clarify a Reformed Christian approach in regard to this topic and then review the studies of the issue in legal and educational aspects in the light of the Reformed perspective. Through reviewing legal and educational discussions, I argue that Christian schools are necessary for people to exercise their religious freedom and make a society more moral and spiritual and thus deserve receiving public aid. Nevertheless, public aid to religious schools needs to be carried out in a careful, restricted way.