Fe_76.5-xSi_13.5B₉Cu₁Al_xalloys were fabricated by arc melting method plus copper mould casting technique. The effects of Al content on the microstructures and mechanical properties of the alloys were investigated. The results showed that the Al content significantly affects the microstructures and mechanical properties of the alloys. The addition of Al element into the alloy results in a variation from nanostructures to coarse grained structures. At the same time, the hardness and elastic modulus decrease with increasing the Al content.