A cubic boron nitride sintered body is provided having improved strength and hardness for serving as a cutting tool. The sintered body includes cBN dispersed in a binder material, wherein the binder includes alumina, at least one other aluminum compound, and a non-aluminum material such as a carbide, nitride, carbonitride, boride or silicide of Groups IVa, Va, and VIa of the periodic table, or a mixture thereof.