In this study, mathematical substructure of works of Dutch graphic artist M.C.Escher is examined. Mathematical effects in Escher's works can be classified in certain topics. Most important of them can be put in order as regular division of the plane, visual paradoxes and fictions on structure of perspective and geometrical topology. For each of these topics, it can be said that Escher is influenced by some certain names as well. Most important of them are Harold Coxeter, Roger Penrose and Albert Flocon. In the first part, relationship between mathematics and plastic arts is examined in general. In the second part, the life and early works of M.C. Escher are examined independently of maths. In the third part, mathematical side of Escher'sworks are studied under certain topics and in relation with some mathematicians.