In order to mitigate primary water stress corrosion cracking (PWSCC) of dissimilar metal weld (DMW) in the primary coolant system of pressurized water reactor (PWR), a heat treatment has been considered. However, the heat treatment conditions should be carefully determined to prevent detrimental effect on the materials in the DMW region. In this study, changes in the mechanical property of materials in DMW and degree of sensitization of SS were evaluated for various heat treatment conditions. In addition, material properties variation and sensitization within the heat affected zone (HAZ) were investigated after the application of the heat treatment condition of 600 degrees C for 10 h, which is considered as the representative heat treatment condition. Based on the test results, it was found that the application of the representative heat treatment condition (600 degrees C for 10 h) would result in negligible detrimental effect on the mechanical properties of materials in DMW and sensitization of SS.