The low-frequency damping characteristics of a new kind of titanium alloy TNCH-Z after different heat treatment were investigated by means of DMA (dynamic mechanical thermal analysis) with the frequency, strain and temperature varying. And audio internal friction was measured. The results show that the damping performance of the alloy is increased greatly with strain amplitude increasing under low-frequency at room temperature. The damping capacity of the alloy is decreased with the frequency increasing. Due to the martensitic transformation, the alloy is sensitive to temperature change. Between –50 oC and 100 oC, the internal friction peak value (tan φ) is 0.08 (heating)/0.09 (cooling). The value of internal friction in the martensitic is higher than that in the mother phase. Because of the influence of the heat treatment system, the internal friction peak of the alloy is wide and the temperature is increased. The audio internal friction reaches to the 10-2 level.