The Environmental and Economic Dispatch problem (EEDP)[9, 6] is a nonlinear Multiobjective Optimization Problem (MOP) which simultaneously satisfies multiple contradictory criteria, and it's a nonsmooth problem when valvepoint effects, multi-fuel effects and prohibited operating zones have been considered. It is an important optimization task in fossil fuel fired power plant operation for allocating generation among the committed units such that fuel cost and pollution (emission level) are optimized simultaneously while satisfying all operational constraints. The purpose of this paper is to use smoothing functions with the gradient consistency property [2] to approximate the nonsmooth EEDP. Our approach based on the smoothing functions, where a sequence of smooth multiobjective subproblems that progressively approximate the nonsmooth multiobjective problem is presented. We show that any accumulation point of a selected subsequence of the iteration sequence generated by the smoothing MOP algorithm is a Clarke stationary point. So the Pareto optimal solutions (stationary
points) of the approximate problems converge to a Pareto optimal solution (stationary point) of the original multiobjective programming problem.