Abstract: ZA27 is zinc alloy which is modified by adding rear earth and Ti, solid-solution and naturally aging. The damping properties of ZA27 and its mechanism are studied. The effect of modification, solid solution and natural aging treatment on damping properties is analyzed. Compare with cast alloy, the damping properties of ZA27 alloy treated by modification, solid-solution and natural aging gets obvious improvement. It is because of microstructure refinement, an increase in boundaries and dislocation multiplication.