Abstract: FeCoSiB films were deposited on flexible substrates by magnetron sputtering.The influences of sputtering gas pressure,bias magnetic field and testing frequency to the stress impedance effect of the films were studied.The results show that the optimized sputtering pressure is 1.5 Pa and stronger bias magnetic field can induce stronger uniaxial transversal magnetic anisotropy,thus the stress impedance effect of the films is increased obviously.When the testing frequency increases from 0.1 MHz to 30 MHz,the stress impedance effect of the films increases.