Fe-(3∼6.5wt%) Si alloy powders having a high magnetic induction(Bs) and a low core loss value for high frequency use were obtained by an extractive melt spinning as well as a centrifugal atomization technique. Sintered core rings made by the rapidly solidified Fe-6.5wt% Si powders exhibited the high frequency magnetic properties : megnetic induction(B8) of 1.23 T, coercivity(Hc) of 0.12 Oe, relative permeability(${mu}$a) of 6321, and core loss(W10/50) of 1.27 W/kg from the rings of 1.1 mm thick. The magnetic induction values were found to be almost identical to those of non-oriented Fe-6.5wt% Si steel sheet and double the value of 6.5wt% Si sheet prepared by the CVD technique. The high frequency core losses(W) up to 10 kHz(W10/10k) were measured to be competitive to those of grain-oriented Fe-6.5wt% Si steel sheet.