Abstract: The paper deals with a problem of global emission optimization using genetic algorithms in diesel engine with electrical unit pump,based on the experimental conditions of nation Ⅲ 13 stages cycle.The engine parameters controlled in the optimization was injection timing.The optimization goal is to minimize specific consumption(BSFC) with respect to the nationⅢ emission standard.The optimum results showed significant improvements for the NOx and particulate emissions(PM).Moreover,the final optimized results met the nation Ⅲ emissions targets.