As the electrodes of secondary battery are made with sulfur compounds, excellent electrode system of environmental non-toxicity, high specific energy density and low material cost can be obtained. In this study, the $FeS_2$ fine compound powders for active material in the battery were synthesized by mechanical alloying. Fine Fe-53.5 $wt.\%S$ powders of 450 nm of mean size were fabricated by mechanical alloying for 60 hours at the horizontal attritor. As the mechanical alloying time increases, particle size of Fe-53.5 $wt.\%S$ was decreased and steady state of Fe-53.5 $wt.\%S$ compound powders was obtained at 30 hours. Fe-53.5 $wt.\%S$ cathode shows the excellent discharge capacity (1011 mAh/g).