Abrasive　blasting　of　the　back　of　the　welds　were　investigated　on　TC18　alloy　with　EBW,　and　the　fatigue　cycle　life　of　the　original　state　and　abrasive　blasting　back　of　the　jionts　were　tested　under　cycle　stress　650　MPa,　and　the　fracture　surface　were　observed　by　scanning　electron　microscopy　(SEM).　Compared　with　that　of　the　original　joints,　the　morphology　of　the　interface　between　weld　back　and　base　metal　is　changed　for　EBW　joints　with　abrasive　blasting,　which　also　results　in　the　alteration　of　the　dimension　and　quantity　of　the　undercut　in　weld　back.　The　fatigue　cycle　life　is　enhanced　by　3　times　more　than　that　of　the　untreated　weld.