The activation energy and the Avrami exponent for crystallization in amorphous Fe 7 0 . 4 5 W 1 . 5 5 Si 3 B 2 5 are investigated with several methods at isothermal and nonisothermal conditions. The values of the activation energy derived by these methods are in agreement with each other, and the average value is 320 kJ/mole. The values of the Avrami exponent obtained by the different methods are different, and the average value is about 3.16.