This note considers the equilibrium Outcomes of the preference revelation games in the general model of indivisible good allocation introduced by [Sonmez, T., 1999. Strategy-proofness and essentially single-valued cores. Econometrica 67, 677-689]. We adopt the concepts of coalitional equilibria and cores which are both defined in terms of the weak deviation or blocking by a prescribed class of admissible coalitions, We prove that if the solution which induces preference revelation games is individually rational and pareto optimal and the class of admissible coalitions is "monotonic," then the set of coalitional equilibrium outcomes coincides with the core. And we point out that the preceding analysis in the context of marriage problems [Gale, D., Shapley, L, 1962. College admissions and the stability of marriage. American Mathematical Monthly 69, 9-15] is hardly extended to the general model. (C) 2008 Elsevier B.V. All rights reserved.