Abstract: FeCuNbSiB amorphous alloy ribbons with 25 μm thickness and 3.2 mm width were manufactured by single-roller method,the stress impedance effect of ribbons was investigated by 4294A impedance analyzer.The results show when the test frequency is lower,the stress impedance effect of ribbons is smaller,the stress impedance effect of ribbons appeare obvious strengthening along with the frequency elevating;the stress impedance effect of ribbons are changed after annealing,and the stress impedance effect of ribbons is the biggest after 300 ℃×2 h annealing ,At 50 MHz and 1.05 MPa,the stress impedance effet of 300 ℃×2 h annealed ribbons can be reached to 0.97%.but only 0.75% for quenching state ribbons.