Mechanical properties and wear behavior were investigated on Al₂O₃ based ceramics added a variety of carbide or nitride etc. to toughen unless excellent resistance to wear of Al₂O₃ get worse ,and to develop the ceramic tool material which can resist using of heavy cutting. As the results, Al₂O₃ based ceramics added WC and Ti(C,N) had high strength and toughness and showed excellent resistance to wear for cutting of steel or cast iron. A correlation between mechanical properties and wear resistance was confirmed clearly at only the heavy cutting, the wear became smaller as mechanical properties was better. Furthermore, from the results of investigation on the relation between form of wear and wear resistance, it was found that reactive wear must be controlled at the high speed cutting ,and chipping wear must be restrained at heavy cutting to improve the wear resistance.