Abstract: The effects of thermo deformation parameters on the flow stress of TA22 alloy are investigated based on the results of the isothermal constant strain rate compression tests. The results show that the flow stress of TA22 alloy is sensitive to strain rate and temperature, reducing with the increase of temperature and the decrease of strain rate. The constitutive equation of TA22 alloy is established base on power function equation and Z-H parameter and by introducing strain parameter. The relative error between the calculated and experimental flow stresses is 7.3%. The constitutive equation can describe the flow behavior of TA22 alloy in the course of high temperature deformation exactly.