Abstract: To forecast fatigue strength or fatigue life of the bogie frame of a high-speed train effectively,a method for fatigue strength forecasting based on tested spectrum loads was proposed.First,with this method,test loads and their cycle numbers for fatigue strength of the bogie frame based on the criteria UIC515-4 and UIC615-4 are graded by using the rain-flow counting method.Second,tresses in the bogie frame under each level of loads are calculated by using the finite element method,multiaxial stresses are changed into a uniaxial stress,and the equivalent stress in the frame is calculated by using the Palmgren-Miner linear cumulative damage hypothesis.Finally,the fatigue strength or fatigue life of the frame is forecasted on the basis of the S-N fatigue life curve.A calculation example shows the validity of this method.