Let G = ( V, mu, sigma) be a fuzzy graph on a finite set V. A fuzzy subset mu' of mu is called a fuzzy dominating set of G if, mu' (nu) + Sigma(x is an element of v)(sigma( x, nu)Lambda mu'(x)) >= mu(nu) for every v.is an element of V. Fuzzy domination number.fz is defined accordingly. In this paper we initiate a study of this parameter. Some properties of fuzzy dominating sets are studied and fuzzy domination number.fz is determined for some graphs.