The Perminvar effect has been investigated in amorphous Fe80-xCrxSi6B14 (x = 0-14 at.%) alloys. The field dependence of the susceptibility of the alloys investigated does not obey the Rayleigh law chi =a+bH, but is constant up to a critical field (H-cr). The Perminvar effect is a result of the magnetic relaxation and therefore, H-cr depends both on the time and the temperature of the demagnetized state stabilization. The addition of decreases the critical field H-cr at which the susceptibility increases as a result of the irreversible movement of the domain walls. The obtained results are compared with the magnetic after-effect (MA-E) investigations which show the non-monotonic decrease of the MAE peak as a function of Cr content.