Fracture mechanics calculation, fatigue test using a full scale axle and investigation on the accuracy of current ultrasonic test are performed to improve the efficiency of routine inspection work of Shinkansen vehicle axles without losing their safety. As allowable cracks, we propose a crack of 3 mm depth at the inner end of gear-side wheelseat, the most important part of an axle for inspection, and a crack of 2 mm depth at the central non-fitted part of axle which is apt to be damaged in running, because such cracks don't propagate for good. Finally, we discover that it is possible to omit the magnetic particle portion of the bogie inspection for Shinkansen vehicle axles provided the service stress and the residual stress are kept almost at the current level.