SCC in L-grade stainless steel components with heavy surface cold work has been reported. Plastic strain introduced by cold work during fabrication process is an important factor for SCC. In order to clarify the relationship between SCC susceptibility in high temperature water and plastic strain, misorientation obtained from EBSP (Electron Backscattering Pattern) method has been carried out. Misorientation vs. hardness (HV) curve of Type 316L and Type 304L was divided into two stages, and the boundary hardness around HV300 was reported to be a critical hardness for the TGSCC susceptibility. In the case of HV<300, misorientation by EBSP was considered to be relating to the dislocation density and have linear relationship between the plastic strain, hardness and yield strength. Therefore, SCC susceptibility in high temperature water can be estimated quantitatively the amount of plastic strain to the critical plastic deformation. Furthermore, in order to examine the possibility of the hydrogen assisted cracking on SCC of L-grade stainless steels with heavy cold work, the amount of hydrogen absorption was analyzed. The amount of hydrogen absorption in hydrogen charged Type 316L increased with the increasing of cold work ratio. It is considered that the dislocation introduced by cold work would be the trap site of hydrogen. In this report, the effect of water chemistry has been also investigated and it was found out that the SCC of L-grade stainless steels with heavy cold work occurred both O2 saturated condition and H 2 + N2 condition.