Effects of ball-milling parameter on structures and properties of sintered Mg-l.5Zr (mass fraction, %) alloy were researched by metallographic analysis, mechanical properties tests and DMA technology. The results indicate that with 310 r/min rotation speed, the microstructure of the sintered alloy is greatly refined, and Zr-phase distributes uniformly. The micro-hardness, bending strength and damping capacities are the greatest under 310 r/min rotation speed. The damping peak of sintered Mg-l.5Zr alloy increases with increasing frequency under the testing conditions. The relaxation time meets the Arrhenius relationship, and shows the characteristics of relaxation damping.