The effect of the addition of Co and N and subzero treatment on tensile strength and damping capacity was investigated in Fe-Cr-Mn alloy. Austenite was transformed into martensite by cold rollins increasing the degree of cold rollins led to an increase in the volume fraction of martensite. The damping capacity linearly increased with increasing volume fraction of ${varepsilon}$ martensite in cold rolled specimens and subzero treated specimens after cold rolling. The volume fraction of ${varepsilon}$ martensite, tensile strength and damping capacity was also increased by the addition of Co, while this treatment decreased the elongation. However, the volume fraction of ${varepsilon}$ martensite, elongation and damping capacity were reduced by the addition of N, although the tensile strength increased. Tensile strength and damping capacity werealso increased by subzero treatment, while elongation decreased.