The deformation behavior of TC27 titanium alloy at the strain rate of 0.01~10s-1 and the temperature of 900~1150℃ was investigated and established the constitutive equation during the hot compression in the machine of Thermecmastor-Z. The conclusion indicates that the material was sensitivity to temperature and strain rate. At the beginning of deformation, the flow stress increases quickly with the augment of true strain and decreases slowly when stress reaches to the maximum value, finally, tending to relatively stable condition. The flow stress decreased with the increase of temperature and increased with the increase of strain rate. The change of flow stress with strain rate and temperature can be described by the constitutive equation during hot compression processing. The active energy of deformation is 300 kJ/mol