A coalition in a graph G = (V, E) consists of two disjoint sets V1 and V2 of vertices, such that neither V1 nor V2 is a dominating set, but the union V1 , V2 is a dominating set of G. A coalition partition in a graph G of order n = |V| is a vertex partition π,= {V1, V2, …, , Vk} such that every set Vi either is a dominating set consisting of a single vertex of degree n-1, or is not a dominating set but forms a coalition with another set Vj. Associated with every coalition partition π,of a graph G is a graph called the coalition graph of G with respect to π, , denoted CG(G,π, ), the vertices of which correspond one-to-one with the sets V1,V2,…, , Vk of π,and two vertices are adjacent in CG(G,π,) if and only if their corresponding sets in π,form a coalition. In this paper, we initiate the study of coalition graphs and we show that every graph is a coalition graph.