Response　conflict　can　be　induced　by　priming　multiple　responses　competing　for　control　of　action　in　trials.　The　N2　is　one　functionally-related　cognitive　control　index　for　response　conflict.　And　yet　the　underlying　whiter　matter　neural　substrates　of　inter-individual　difference　in　conflict　N2　remain　unclear.　So　the　aim　of　present　study　was　to　address　the　white　matter　microstructure　of　the　N2　responsible　for　conflict　by　directly　relating　the　amplitude　cost　of　the　event-related　potential　(ERP)　N2　component　to　diffusion　tensor　imaging　(DTI)　indices　in　healthy　subjects.　Thirty　healthy　subjects　underwent　DTI　scanning　and　electrophysiology　recording　during　a　modified　Flanker　task.　N2　was　a　stimulus-locked　negative　ERP　component.　Fractional　anisotropy　(FA)　was　calculated　based　on　DTI　measures　and　was　assumed　to　reflect　the　integrity　of　myelinate　fiber　bundles.　Therefore,　we　tested　the　relationship　between　N2　amplitude　and　FA　in　brain　white　matter.　Results　showed　that　FA,　an　index　for　white　matter　characteristics,　in　the　right　superior　longitudinal　fasciculus　(SLF)　was　significantly　positively　associated　with　N2　amplitude　cost.　The　N2　amplitude　cost　also　predicted　response　time　(RT)　cost　in　the　Flanker　task.　Higher　FA　was　associated　with　larger　N2　amplitude　cost,　suggesting　that　changes　in　white　matter　integrity　in　the　SLF　may　account　for　changes　in　efficient　transmission　of　fronto-parietal　modulatory　conflict　signals.　(C)　2017　Elsevier　B.V.　All　rights　reserved.