Abstract: This paper deals with the analysis and design of the damage tolerance for turbine disks. A practical design method is worked out and verified through analysing the damage tolerance of an existing engine. A "twice evaluation algorithm" for evaluating J-integral is provided, in which J is estimated in the light of the linear elastic fracture mechanics, and then a plastic correction with iterative procedure is made to obtain J. On the basis of breakdown tests and elaborate theoretical calculations, a criterion and a solution algorithm for determining the critical crack length are suggested. A method calculating residual life or turbine disk initiating cracks is provided, which is proved practical. The numerical results obtained by this method are in good agreement with the statistics of crack propagation collected from the actual turbine disks.