Fe62Co8-xCrxNb4Zr6B20 and Fe62Co8-xMoxNb4Zr6B20(x=0,2,4, atomic percent) alloy series were chosen to study in this paper based on the three empirical rules of making bulk amorphous alloy. The ribbons, 30μm thick and 5mm wide, were produced by single-roller rapid quenching. The thermal stability, amorphous structure and magnetic properties of these alloys were studied by differential thermal analysis, X-ray diffraction, Faraday magnetic balance and static magnetic measurement. The supercooled liquid region ΔTx of the alloy, which contains 2at% Cr, reaches 85K, but the saturation magnetization σs of these alloys decreases distinctly with increasing Cr or Mo. The saturation magnetization σs and coercive force Hc increase rapidly for the alloys of this series annealed at 973K for 900s because of the precipitation of α-Fe.