Fe40Co40Zr9B10Ge1 and Fe40Co40Zr5Mo4B10Ge1 amorphous alloys were prepared by melt-spinning and annealed at different temperatures. The microstructure and magnetic property of the alloys were tested and analyzed by XRD and VSM. The effect of Mo addition on the crystallization and magnetic property of Fe40Co40Zr9B10Ge1 alloy was studied. The results show that α-Fe(Co) phase precipitates from amorphous matrix at the initial stage for two alloys. However, the crystallization products after high-temperature heat treatment are different. The addition of Mo reduces the content of metal compounds at high-temperature. The addition of Mo reduces the grain size of α-Fe(Co) precipitated during crystallization. The addition of Mo also reduces the coercivity.