This　paper　investigates　the　effect　of　steel　fiber＇s　zinc　phosphate　(ZnPh)　treatment　and　shape　on　the　strength　and　toughness　of　ultra　high　performance　concrete　(UHPC)　containing　granite　powders　under　autoclaved　curing.　Steel　fibers　with　four　dfferent　shapes　were　used:　straight　with　copper　plating　(S),　single-linear　hooked-end　with　copper　plating　(G1),　bi-linear　hooked-end　with　copper　plating　(G2)　and　crimped　with　copper　plating　(L).　The　results　obtained　from　customized　single　steel　fiber　pullout　test　and　SEM-EDS　observation　indicated　that　the　mechanical　interlock　is　the　dominating　effect　for　the　enhanced　strength　and　toughness　of　UHPC　containing　granite　powders.　The　average　bonding　strength　and　pullout　energy　are　in　the　order　of　G1　＞G2　＞L　＞S.　The　ZnPh　treatment　modified　the　fiber　geometry,　resulting　in　enhanced　surface　roughness,　which　increased　the　chemical　bonding　and　static　friction　between　the　steel　fibers　and　the　UHPC　matrix,　and　consequently　raised　the　pullout　energy　of　steel　fibers　in　UHPC.　Compared　to　G1,　G2　and　L　steel　fiber,　the　ZnPh　treatment　exhibited　the　most　obvious　effect　toward　S　steel　fiber　in　terms　of　enhanced　toughness　of　UHPC.　©　2017,　Materials　Review　Magazine.　All　right　reserved.