Hot deformation behavior and microstructure evolution of TC11 alloy are studied by hot compression tests．The stress-strain curves appear steady flow softening characteristics at high temperature．A Kumar type constitutive equation fbr TC11 alloy is established by nonlinear regression analysis．Applying this constitutive equation in commercial FEM software of MSC／Autoforge，hot die forging process of TC11 alloy turbine disc is then simulated．The results show that the Kumaur-type constitutive relationship meets the practical need to a great extent．