In order to investigate shot peening on rolling contact fatigue lives of bearing steel, fatigue tests were performed with a thrust testing machine and a roller testing machine. The disks and rollers were treated by shot peening with a shot diameter of 0.05mm. The surface hardness and the surface compressive residual stress of the test specimens were increased by the shot peening. The rolling contact fatigue lives of the test specimens treated by the shot peening were longer than that of the non-peened test specimens. The rolling contact fatigue lives of the disk specimens were improved by the increase in surface hardness due to the shot peening.