Abstract: In this paper, the film cooling effectiveness of rotating gas turbine blade is investigated through numerical simulations. The cooling characteristics under different blowing ratios in rotating state as well as static state are compared in details. The average film cooling efficiency and cooling non-uniformity coefficient are used to evaluate the film cooling effect. The results show that on the pressure surface of the blade, due to the blade rotation the momentum of the jet cooling air in the normal direction will increase after the airflow passes through the film hole and then intensify with the mix of mainstream, such that the film cooling efficiency on pressure surface is lower than that of the static state. While on suction surface the rotation will result in the decrease of the normal momentum of jet air through the film hole, which will make it remain well attached to the surface and move downstream. Therefore the film cooling efficiency on suction surface is higher than that of the static state, and the average film cooling efficiency on the trailing edge is significantly boosted in comparison with the static state. The cooling non-uniformity coefficient on rotating blade is slightly greater than that of the static blade.