Abstract: This paper studies useful life of an areoengine's LPT (Low Pressure Turbine) disk by analysis and experiment.Stress calculation and life prediction are performed to choose the critical location where cracks likely occur.Experiment equipments,specimens and parameters on the basis of equivalent damage principles are introduced.In this paper test results of two specimens are presented,which are used to determine the standard cycles and average flying hours of the disk in accordance with related literature.Test research provided experimental basis for useful life assessment and prolongation of disk.