The　effect　of　titanium　on　the　as-cast　microstructure　of　a　hypereutectic　high-Cr　cast　iron　containing　4.0　wt./carbon　and　20.0　wt.%　chromium　was　investigated.　With　the　increase　of　titanium　concentration,　the　primary　M(7)C(3)　carbides　were　refined　and　the　volume　fraction　of　all　carbides　(primary　and　eutectic　carbide)　was　decreased　gradually.　TiC　particles　became　larger　and　agglomerated　when　the　titanium　concentration　was　1.47　wt.%.　Theoretical　calculation　and　experimental　results　confirmed　that　TiC　particles　form　before　the　precipitation　of　primary　carbides.　The　first　precipitated　TiC　particles　can　act　as　the　heterogeneous　substrate　of　M(7)C(3)　carbides,　which　results　in　significant　refinement　of　M(7)C(3)　carbides.　(C)　2007　Elsevier　Inc.　All　rights　reserved.