.Carbon monoxide oxidation has long been considered by researchers.Reducing air pollution, carbon dioxide lasers and mine rescue devices are only three of the many applications of the carbon monoxide oxidation. Furthermore, due to growing use of fuel cells in recent years, catalytic carbon monoxide oxidation reaction has been used to remove carbon monoxide from fuel cell inlet stream. In this thesis, optimization of operating conditions of catalytic carbon monoxide oxidation reactor was carried out via genetic algorithm. Given that optimization has a major role in process design, so after compiling and proving model, optimization of reaction system using genetic algorithm was accomplished. For this system, by applying process integration, four modes (a mode without heat source as the base case and three modes with the heat source) were considered. Then, considering the total annual cost as the objective function and optimization by genetic algorithm, the appropriate design parameters for four aforementioned cases were determined. According to the results of this study, by preheating the inlet feed of the reactor, more than 60 percent saving in total annual cost was obtained compared with the base case.product stream to preheat the inlet gas stream, which resulted in 40 percent reduction in total annual cost, is a much better design option due to environmental consideration. Keywords: Carbon Monoxide Oxidation, Optimization, Genetic Algorithm, Process Integration , Total Annual Cost