The electromagnetic wave absorption properties of amorphous alloy-epoxy composites have been investigated with various amorphous alloy particle size in a frequency range from 45 MHz to 10 GHz. The composites with small powder size (<26 mum) revealed good absorption properties higher than 20dB with a thin sample thickness less than 6 mm. As the powder size decreased, the matching frequency moved to a higher frequency region. It was found that such a variation of absorption properties - matching frequency and matching thickness - in amorphous alloy-epoxy composites is attributed to the difference of the complex permeability dispersion induced by eddy current effect and magnetic resonance, which independently operate in composite samples according to amorphous alloy particle size.