A computional heat transfer(CHT) analysis was carried out to comprehend the mechanism of rotation and the temperature ratio of the film and the main flow on the film cooling which is important in understanding the mixing process between the film coolant and the hot stream air over the high pressure turbine blades. It was found that both parameters could affect the distribution of the film cooling, which was clearly shown with the film cooling effectiveness distribution graph. On the suction side rotation leads to that the effective film trace bends centrifugally and on the pressure side it inclines centripetally, which is consistent with the direction of the Coriolis force. With the increase of the coolant-to-mainstream temperature ratio, the effective film trace bends centrifugally, which is determined by the increase of the centrifugal buoyancy force. Rotation could lead to the decrease of the film cooling effectiveness. Contrast to this, temperature ratio has little effect on the film cooling effectiveness.