This paper deals with new sequence spaces X(r, s, t; ∆) for X ∈ {l ∞ , c, c 0 } defined by using generalized means and difference operator. It is shown that these spaces are complete normed linear spaces and the spaces X(r, s, t; ∆) for X ∈ {c, c 0 } have Schauder basis. Furthermore, the α-, β-, γ-duals of these sequence spaces are computed and also established necessary and sufficient conditions for matrix transformations from X(r, s, t; ∆) to X.2010 Mathematics Subject Classification: 46A45, 46A35.