The hot deformation behavior of TiAl alloy was analyzed on a Gleeble-3500 thermal mechanical simulator at various temperatures（1 273

1

423K）and strain rates(0.001

1

s

-1

).Constitutive equation based on introducing the strain was established by using multiple linear regression for material constant and true strain relationship.The results reveal that the presented model with six order polynomial fitting can better predict the experimental data on the true stress-strain curve

and relative error is less than 5%.