The Fe-rich alloys of Fe 90-x Si 5 B 5 M x (M= Cr or Mo; x=1, 2) are synthesized in the present study. The as-spun structure mainly consists of bcc phase plus a minor amount of metastable phase (Fe 3 B and/or Fe 23 B 6 ). Comparing with the base alloy Fe 90 Si 5 B 5 , the corrosion resistance is improved significantly due to the formation of the passive film. Saturation magnetic flux density reaches 1.9 T for the melt-spun alloys Fe 89 Mo 1 Si 5 B 5 . The alloys present a nearly constant high permeability in a rather high magnetic field up to coercive field which can be used as a new kind of sensor material with good fundamental properties and low cost.