Hot deformation behaviors were studied by means of scanning electron microscopy (SEM) and uniaxial thermal tension. The effect of deformation temperature and strain rate on flow stress was evaluated, and deformation mechanism was analyzed. The results show that the stress-strain curves of Ti-6Al-4V (TC4) alloy sheet and TC4 alloy bar at elevated temperatures have different forms and rules. Flow stress of TC4 is controlled by both strain rate and deformation temperature. The flow stress decreases with the increase of high temperature. Deformation mechanisms exhibit dynamic recovery and recrystallization feature within high temperature region and grain boundary slip behaviors at low temperature. Hot effect behaviors were studied by means of scanning electron microscopy (SEM) and uniaxial thermal tension. The effect of deformation temperature and strain rate on flow stress was evaluated, and deformation mechanism was analyzed. The results show that the stress-strain curves of Ti Flow stress of TC4 is controlled by both strain rate and deformation temperature. The flow stress decreases with the increase of high temperature. Deformation mechanisms exhibit dynamic recovery and recrystallization feature within high temperature region and grain boundary slip behaviors at low temperature.