the blade of the turbo blisk often cracks due to rotor's resonance. the research on influence degree to the turbine blade mode with different constrains of blisk can gain the universal fixture in the modal tests. for this purpose, the vibrant characteristic of blisk was gained by fem, as well as the modal test of turbine blade was applied in free and intermediate fixed status respectively. the simulation results agreed very well with test ones, which indicated that the influence of blisk constraint can be ignored in modal test when the blisk stiffness is much bigger than the blad.