Generally the generation units in the traditional structure of the electricity industry try to minimize their costs. However, in a deregulated environment, generation units are looking to maximize their profits in a competitive power market. Optimum generation planning in such structure is urgent. This paper presents a new method of solving economic dispatch in the competitive electricity market with the aim of maximizing the total contribution profit of power generation. In this regard, with a combination of two intelligent optimizations, a new efficient algorithm which called improved particle swarm optimization algorithm is suggested. The simulation of the new approach and conventional PSO algorithm were performed on two case study systems, 10-units and 15-units. According to the results, the suggested method not only resolves the convergence problem, but it also makes more efficient response. Manuscript profile