In　this　paper,　laser　weld　technology　was　applied　to　produce　the　welded　joints　of　CLF-1　steel,　which　is　the　primary　material　for　manufacturing　test　blanket　module　(TBM).　The　microstructures　and　mechanical　properties　of　the　joints　were　studied　at　as-welded　state,　post-weld　heat　treatment　(PWHT)　of　710　C/2　h/air　cooling　(PWDT),　and　PWHT　of　980　C/1　h/air　cooling　(AC)　followed　by　tempering　at　710　C/2　h/AC　(PWNT).　The　results　showed　that　abundant　lath　martensite　phase　with　width　800　nm　and　small　amount　of　delta-Fe　phase　were　present　in　the　weld　at　as-welded　state.　Its　impact　toughness　was　about　40　J.　The　microstructures　of　the　weld　at　PWDT　state　included　a　large　amount　of　tempered　lath　martensite　with　width　650　nm,　few　delta-Fe,　M23C6　carbide　(distributed　along　the　boundary　of　martensite)　and　MX　carbide　(precipitated　inside　the　martensite).　Its　impact　toughness　was　about　237　J　(equivalent　to　the　base　metal).　The　microstructures　of　the　weld　at　PWNT　state　included　a　large　amount　of　tempered　lath　martensite　with　width　350　nm,　M23C6　carbide　and　MX　carbide.　Even　though　the　delta-Fe　phase　disappeared,　the　impact　toughness　(about　156　J)　was　lower　than　that　of　the　weld　at　PWDT　state　due　to　the　aggregated　growth　of　M23C6　and　MX　carbides.