The efects of surface stress amplitude on damping capacity of new CuAlMn shape memory alloy were examined based on tracing filter technique by measuring deamplification capacity of the alloy in the first and second resonant frequency using cantilevered bending resonant unit at a surface stress amplitude in the range of 4.05～ 40.5 MPa. It was found that the CuAlMn shape memory alloy may possess higher damping capacity in parent phase（ Q -1 max =0.12）

martensite and dual phase either.The overall damping capacity decreased with increasing in the surface stress amplitude.The damping capacity decreased faster in the alloy with parent phase than with martensite below a critical stress while decrease in damping capacity trended evenly over critical stress

slightly dependent on the microstructure.