The aluminum alloy axle box is used for 600km/hour high speed train , The tensile and fatigue properties of the 7050aluminum alloy used for the die forging axle box of high speed train weremeasured and analyzed. The experimental results showed that the tensilestrengths and ductilities of the specimens parallel to extension of metalduring forging (L specimen) were higher than that of the specimensperpendicular to the direction of the extension of metal (T specimen) . And thefatigue limit of the specimens parallel to extension of metal during forging (Lspecimen) )wasσ D=190 Mpa, which was  higherthan that of the specimens perpendicular to the direction of the extension ofmetal (T specimen)i.e., the fatigue limit of the T specimens wasσ D=178.3MPa. The fracture surface morphology obvervation revealed that the fracture surfaceof L specimens were dimple, but the fracture surfaces of T specimens wereintergranular...