Based on the operation data collected from a certain power plant,it is found that the temperature distribution on stator core between turbine end and exciter end is quite nonuniform,furthermore,there exists some overheated step core in the step iron.By means of numerical analysis,it is found that the volume flow of radial vent channel beside the overheated step core is quite low compared with other adjacent radial vents.The overheat problem was resolved by increasing the height of the baffle locating in the inner step iron,and the test data support the above measure.Some useful conclusions were given for the future optimum design and unit capacity enlargement.