For decision support under a multi-objective environment, it is effective to offer a Pareto optimal solution set with uniform distribution to the decision-maker. In this paper, a new optimization method for obtaining a Pareto optimal solution set with such uniform distribution is proposed. In order to overcome the difficulty of realizing this goal, the concept of cannibalism is introduced in BUGS (a bug-based search strategy using genetic algorithms). Introducing the concept of cannibalism achieves the uniform distribution of Pareto optimal solutions. A numerical experiment using typical continuous and discrete multi-objective optimization problems clarifies the usefulness of the proposed method.