A rolling contact fatigue test was carried out under a traction oil lubricating condition and the test result was compared with that under a turbine oil lubricating condition. The minimum film thicknesses under both lubricating conditions were almost equal. The failure mode of both lubricating conditions was pitting caused by surface cracking. The rolling contact fatigue strength under the traction oil lubricating condition was greater than that under the turbine oil lubricating condition. The cracks observed on the roller surfaces tested under the traction oil lubricating condition were the longer along the axial direction of the rollers.