Abstract: This study was carried out to investigate the effect of cold working on the damping capacity of Fe-27Mn-4Co-2Al-3Si alloy. αʹ and ε-martensite were formed by cold rolling, and these martensite was formed according to the specific direction, surface relief and partially intersection. With the increasing degree of cold rolling, amount of αʹ-martensite was rapidly increased, whereas amount of ε-martensite was decreased after rising to maximum value at specific lever of cold rolling. Damping capacity increased and then decreased with an increase in degree of cold rolling. Damping capacity was greatly influenced by the volume fraction of ε-martensite formed by cold rolling, but the effect of volume fraction of αʹ -martensite on the damping capacity was not observed. Damping capacity of cold rolled Fe-27Mn-4Co-2Al-3Si alloy was effected by the amount of αʹ-martensite.