In　this　paper,　we　investigated　the　effect　of　titanium　modification　on　microstructures　and　properties　of　carbidic　austempered　ductile　iron　(CADI)　containing　3.72wt.%　C,　2.77wt.%　Si,　and　0.51wt.%　Mn.　The　results　showed　that　with　the　addition　of　0.1wt.%　Ti,　TiC　particles　were　formed,　and　distributed　in　carbides　and　matrix.　Microstructural　observation　indicated　that　the　maximum　diameter　of　graphite　nodules　decreased　from　58　to　40m,　and　the　shape　of　carbides　transformed　from　network　to　fragmentation,　which　was　related　to　the　nucleation　of　the　eutectic　structure　(+(Fe,　Cr)(3)C)　where　TiC　particles　act　as　the　nucleus.　After　isothermal　quenching　at　300　degrees　C,　the　hardness　of　Ti-bearing　CADI　was　3.5　HRC　higher　than　ordinary　CADI,　and　the　impact　toughness　was　increased　by　14.3%.　Additionally,　due　to　the　decrease　in　exfoliation,　the　wear　loss　of　Ti-bearing　CADI　was　14.8%　lower　than　ordinary　CADI　during　the　block-on-ring　wear　test　at　the　surface　load　of　300N.