This paper focuses on analysis of mathematical being in Aristotle’s philosophy. In a brief introduction, the author endeavours to present the sources as well as the attitude of Greek thinkers towards mathematics, which is, for the first time in the history of European thought, treated as science, that is, knowledge that serves its own purpose. In addition, the author explicates Aristotle’s general attitude towards mathematics, which is followed by ontological analysis of mathematical being in next chapter. This analysis is extended in a representation of the relationship between the problem of universals and the determination of the nature of a mathematical object as an abstraction, thereby rendering it as the transparent relative way of existence of the mathematical being. Furthermore, the author presents Aristotle’s conception of space and time as values that are at the same time possibilities of abstraction of the mathematical being. After the process of abstraction, mathematical objects are observed through a cathegorical scheme, as they are in their ontological mode of being.