The aim of this paper is to analyze Leibniz and Newton’s conception of space, and to point out where their agreements and disagreements lie with respect to its mode of existence. I shall offer a definite characterization of Leibniz and Newton’s conceptions of space. I will show that, according to their own concepts of substance, both Newtonian and Leibnizian spaces are not substantival. The reason of that consists in the fact that space is not capable of action. Moreover, there is a sense in which space is relational, because their parts are individuated only by means of their mutual relations.