Abstract: Bearing ring blank 105 mm in diameter by 21 mm thick,made from GCr15 steel,was found cracking after oil quenching. The chemical composition analysis,hardness test and metallographic examination were performed on the cracked bearing ring blank for the purpose of revealing the cause of its cracking. The results showed that the chemical composition,hardness and microstructure of the cracked bearing ring blank all conformed with the specification,however,the through crack appeared on the blank surface,and the decarburization appeared around the crack and at the end of the crack,indicating that the crack emanated from forging. The cracking of the bearing ring blank was traced to forge crack.