Cutting tests had been done on the Austempered Ductile Iron (ADI) with ceramic cutting tools. The wear shape of the cutting tool’s surface was observed by the Scanning Electron Microscope (SEM). The micro-wear area of the tools was analyzed with energy spectrum. Study on wear shape and wear mechanisms were done when infeed cutting ADI. The result shows that: the cutting speed is an important factor to the tool wear when infeed cutting ADI with CC650 tool, and with the increase of the cutting speed, the wear value of cutting tool increases obviously. The flank of cutting tool (CC650) has wear land of definite width during cutting, and shows obvious abrasive wear. The crate wear shape of rake face is almost joined to major cutting edge, it is different from the typical crate shape of rake face. Elements Fe, Si and Mg in ADI material diffuses to the surface of cutting tools (CC650) after cutting, the diffusion exacerbates the wear of cutting tools, and the diffusion degree of rake face is larger than that of flank, abrasive wear, adhesive wear and diffusive wear is chief reasons for tools wear.