The core material of supercritical water cooled reactor(SCWR)is one of the sticking points for SCWR,while the operational conditions of supercritical unit(SCU)are greatly similar to SCWR.Me-chanical property,operating temperature and service environment for the materials of both the core of SCWR and the boiler of SCU were compared and discussed.Candidate materials of supercritical water cooled reactor were been put forward in this paper,such as T23,T91,T122,316,TP347H(FG)and Super304H.