Fe40Co40Zr(10-x)MoxB9Cu1(x=0,2,4) amorphous alloys were prepared by the single roller melt-spinning and isothermally annealed at different temperatures. Microstructures, thermal properties and magnetic properties of the samples were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), differential thermal analysis (DTA) and vibrating sample magnetometer (VSM). The results show that the apparent activation energies of Fe40Co40Zr(10-x)MoxB9Cu1(x=0,2,4) alloys decreases with the increase of the Mo content. Mo addition reduces the thermal property of the alloys. The increase of Mo content inhibits the precipitation of ZrCo3B2 compounds and refines the grain size of the alloys. Coercivity (Hc) of Fe40Co40MoxZr(10-x)B9Cu1(x=0,2,4) alloys increases with the increasing of annealing temperature gradually. Mo addition reduces the Hc obviously.