Stress　corrosion　cracking　(SCC)　of　welded　joint　is　one　of　the　salient　problems　influencing　the　safety　of　nuclear　power　structure.　In　this　work,　laser　shock　peening　(LSP)　was　introduced　to　enhance　the　corrosion　resistance　of　Ni-base　Alloy　600　welded　joint.　The　corrosion　behavior　was　evaluated　by　electrochemical　corrosion　and　SCC　tests,　and　its　anti-corrosion　mechanism　was　analyzed　in　terms　of　the　residual　stress　and　microstructure　evolution.　The　results　indicate　that　LSP　treatment　could　significantly　reduce　the　electrochemical　corrosion　rate　and　SCC　sensibility　of　the　weldments　by　81　%　and　14　%,　respectively.　The　enhanced　corrosion　resistance　of　the　welded　joint　was　attributed　to　the　compressive　residual　stress　and　high-density　dislocation　tangles　induced　by　LSP.　The　maximum　compressive　residual　stress　of　~460　MPa　in　weld　zone　could　be　obtained　with　the　laser　power　of　25　J.　The　microstructure　evolution　of　LSP　for　weld　zone　and　base　metal　is　dominated　by　the　dislocation　activities.