This article deals with the effects of a blowing ratio measured with narrowbend liquid crystal in transonic experiments on the heat transfer characteristics of trailing edge cutback. The experimental results are compared end contrasted in terms of available data for tra-ditional experiments with thermocouples. It is concluded that the blowing ratio exerts rather significant effects on film cooling effec-tiveness distribution of the rib center line. As the blowing ratio decreases, similar to the cooling effectiveness distribution curve of the slot center line, that of the rib center line makes a clockwise rotation about the end. When the blowing ratio increases, the regular film cooling effectiveness curve of the surface becomes rather smooth. On the whole measuring surface, the most intensive heat transfer oc-curs at the extended borderline of the slot end the rib, neither at the rib center line nor at the slot center line. The experimental results of cooling effectiveness measured with thermocouples are lower than those with liquid crystal. In addition, the transient experiments using narrowband liquid crystal can eliminate the higher errors of Nusselt numbers in measurements with thermocouples at the slot outlet.