Introduction: Let G be a simple undirected graph over the vertex set V. Let I(G) denotes the edge ideal of G and DG be the simplicial COMPLEX whose faces correspond to the independent sets of G. This simplicial COMPLEX reflects many nice properties of G. A simplicial COMPLEX D is called SHELLABLE if the facets can given a linear order F1,…,Ft such that for all 1£t<f£s, there exists some vÎF1\Ft and some LÎ{1,…,f-1} with F1\Ft={v}. A result due to Hochster says that every pure SHELLABLE COMPLEX is Cohen-Macaulay over every field. A graph is called SHELLABLE, if the simplicial COMPLEX DG is a SHELLABLE simplicial COMPLEX.Aim: In this paper we focus on the question of what graphs G have the property that `G is Cohen-Macaulay, i.e. R/I(`G) is Cohen-Macaulay. We prove that the complement of a connected triangle-free graph is pure SHELLABLE and consequently Cohen-Macaulay.Methods: By providing an explicit shelling for the facets of D`G, whenever G is a connected triangle-free graph, we show `G, the complement of G, is pure SHELLABLE and consequently Cohen-Macaulay.Conclusion: The complement of any connected bipartite graph and any cycle is pure SHELLABLE and hence Cohen-Macaulay.