The fretting fatigue behavior of TC4 titanium alloy was investigated using a cylinder-plane configuration. Through the observation of worn surface and cross-section, the formation and evolving process of the fretting debris and the effects during fretting fatigue were discussed. The variation of friction coefficient with time was analyzed. Based on the experimental results of TC4 titanium alloy, it is found that the damage mechanism of fretting fatigue was adhering wear, abrasive wear and contact fatigue, accompanying with oxidation wear. The fretting debris were formed from the break-off and crushing of the parent alloy, then oxidization to be the fragments during the fretting fatigue test. It promoted the abrasive wear and accelerated the fatigue failure due to the hard oxide particles in fretting debris. The friction coefficient rapidly increased with time in the initial stage, then kept stable in the stable stage.