Abstract: The effects of electromagnetic stirring on the primary austenite in the cast iron and as-caststructures of the spring steel was studied.The experiments had shown that the primarily large austenitic dendrites can be fined when stirred by electromagnetic field for a short time and the higher the stirring power,the more sphercal or dedendritic the primary austenite,and that the fluid flow and temperature fluctuation of the melt may be induced by stirring,and accelerate the remelting of the second arm and decrease of the length of the first arm so that the primarily dendritic austenite is changed to spherical shape finally.That the column dendrites of the samples of spring steel can be also fined by the strong electromagnetic stirring and changed into fine equiaxed grains.