The stress-inductance characteristic of ferrite-glass composites has been studied with special emphasis on the effect of heat treatment and glass chemistry. The stress-inductance relation of Ni-Cu-Zn ferrite has been greatly improved by incorporating glass and by quenching from high temperature. The effect of quenching temperature on the stress-inductance characteristic is discussed in terms of the bending strength and fracture mode of the composites, and creep and microcrack formation during quenching are proposed as responsible factors.