Film cooling performance under rotating condition was investigated in rotor blade of a 1.5-stage turbine using Thermochromic Liquid Crystal (TLC) technique. The turbine is installed in the middle of the experimental apparatus which is a closed-loop, low-speed thermal wind tunnel. The rotor of the turbine includes 18 blades with chord of 124.3 mm and height of 99 mm. A film hole is set in the middle span of rotor blade surface with injection angle of 28 degrees on the pressure side and 36 on the suction side respectively. In the experiments, the Reynolds number based on the mainstream velocity of the turbine outlet and the chord length of the rotor blade is fixed at 1.89 x 10(5). Measurements are made at three different rotating speeds of 600 rpm, 667 rpm and 702 rpm with the blowing ratio varying from 0.3 to 3.0. CO2 and air act as coolant to obtain the density ratio of 1.57 and 1.03, respectively. The effects of blowing ratio, density ratio, rotating number and curved surfaces are analyzed according to the film performance. Comparing with the air injection, the CO2 injection with higher density ratio produces better film attachment. The film coverage and cooling effectiveness increases monotonously on the pressure side while the trend is parabola on the suction side as the blowing ratio rising. The film deflection is analyzed quantitatively. Higher rotating number and lower blowing ratio results in stronger film deflection. Besides, the different characteristics are indicated between the pressure side and the suction side. (C) 2013 Elsevier Ltd. All rights reserved.