The operation optimization of the steam power unit is important to the normal operation of the unit and it has now proved to be a key technology in steam power plants.In this paper,sensitivity analyses for the main per-form ance parameters of one 300 MW coal-fired power unit are carried out to reveal the effects of parameter deviations on the gross coal consumption rate.The results show that the deviations per engineering unit of 6 parameters,namely,the carbon content of the fly ash,the oxygen eontent of the flue gas in the furnace chamber outlet,the flue gas temperature,the condensate depression,the feed-water temperature and the main-steam pressure,greatly influ-ence the gross coal consumption rate.Then,an optimization model with the minimum gross coal consumption rate as the object function is established,to which the optimum solution is obtained by genetic algorithm.Moreover,a software for the operation optimization of the steam power unit is developed,which is finally applied to the opti-mized calculation of the unit.Thus,an operation scheme with optimal parameters is obtained.With the new opera-tion scheme,the gross coal consumption rate decreases by about 1.41 g/(kW ·h).