Abstract: Two-dimensional unsteady Navier-Stokes simulations were applied to the cascades of the typical first-stage turbine blade and second-stage guide vane to study the effects of combustor hot streaks on the flow and temperature fields.The predicted results show that the existence of hot streak has small impacts on the time-averaged static pressure around the turbine blade airfoils,but will increase the unsteadiness of static pressure around the first-stage rotor blades and second-stage guide vanes.The simulations verify the facts of the blade pressure surface overheating induced by the hot streaks, and there is similarly effect on the increase of the guide vane pressure surface temperature.