Abstract: Through on-site oxide scale skin inspection and lab analysis of final stage superheater of a power plant boiler which has operated for about 130 000 hours, the residual service life of superheater tubes is predicted. The distribution of oxide scale thickness measured on-site perfectly matches with the tube wall temperature distribution measured, which can fairly reflect the actual temperature distributions of final stage superheater tubes; the results of laboratory comparative analysis have verified that the measurement by using inner wall oxide scale thickness gauge is reliable. The life prediction results show that the minimum remaining life of the sample tube is 46 834 hours. It is suggested that there is still large margin for residual life of final stage super heater tubes, and monitoring should be strengthened, while inspections of oxide scale thickness be regularly carried out.