LetR,Sbe rings with unity,Ma module overS, whereSa commutative ring, andf:R→Sa ring homomorphism. A ring representation ofRonMviafis a ring homomorphismμ:R→EndS(M), whereEndS(M) is a ring of allS-module homomorphisms onM. One ofthe important properties in representation of ring is the Schur’s Lemma. The main result of thispaper is partly the generalization of Schur’s Lemma in representations of ring on modules over acommutative ring2010 Mathematics Subject Classifications: 16G10, 16W20, 12E15Key Words and Phrases: Representation of ring on module, Generalized Schur’s Lemma, Ringhomomorphism.