Turbocharger turbine blade are exposed to damage because of High pressure and Pulsating inlet charge. In recent designed blades, thickness is reduced and loading was increased, these caused the higher probability of blades failure. Therefore the blades thickness distribution should be defined according to the combination of higher efficiency and higher resistance against failure. In this paper the Aero static efficiency of the turbine according to different thickness parameters is studied. And the most vulnerable area of the blades is identified by the result of the fluid behaviour simulation and structural analysis. A 3D CFD model in ANSYS CFX for fluid side, and a FEA model in ANSYS Static Structural module for the blade structural responses were used then the results were coupled. Validation was performed by reference to experimental data. Results show that thinner blades are more proper for this kind of his kind of turbomachine but in partial admission ticker blades have higher efficiency than thinner blades.