In all of power plants, which are made only for electricity generating, more than half of fuel energy is wasted. This waste energy could be recovered by cogeneration or trigeneration systems. In this study a cogeneration combined cycle with triple pressure HRSG has been simulated. Second product was considered heat that can be generated as steam or hot water depends of intended consumption. At first, exergy and energy analysis has been carried out and potential of waste heat in power plant was determined and evaluated. By using TRR method Thermoeconomic analysis was done and cost of products calculated. At the end of this research an objective function defined and to optimize with algorithm Genetic method, some decision variables were selected. After various parameter optimizations at different situation of power plant, optimum structure specified. Results are shown at which status of power plant, producing heat and power has maximum efficiency and profitability.