Fatigue crack propagation behaviors of Ti-6Al-4V alloys, produced through different thermomechanical processing routes, were examined at 25 and 316℃. The microstructure containing acicular α+β phases in the coarse prior β grain demonstrated better resistance to fatigue crack propagation (FCP) than equiaxed α+transformed β or α` structures. The crack tortuosity and crack closure in the acicular α structure were higher than those of the other microstructures, which was believed to be responsible for the improved FCP resistance. At 316℃, both equiaxed α+ transformed β and α` structures did not show any degradation in FCP resistance. For acicular α structure which showed the highest FCP resistance at room temperature, on the other hand, the crack tortuosity was greatly reduced and, resultantly, FCP resistance was reduced at 316℃.