Amorphous Fe80−xNbxB20 (x = 5, 10, 15) ribbons were prepared by single-roller melt spinning method. The thermal, structural and magnetic properties of Fe80−xNbxB20 (x = 5, 10, 15) ribbons were investigated using dierential thermal analysis, X-ray diraction, and vibrating sample magnetometer. The thermal stability is the lowest for Fe70Nb10B20 ribbon and the highest for Fe65Nb15B20 ribbon. Along with the increase of Nb content, the supercooled liquid region ∆Tx increases, indicating that the amorphous formation ability improves. The primary stages of crystallization of the three ribbons are dierent. The primary devitrication phases are Fe23B6 type for Fe70Nb10B20 and Fe75Nb5B20 ribbons, and α-Fe type for Fe65Nb15B20 ribbon. Fe80−xNbxB20 (x = 5, 10) ribbons are ferromagnetic and the Fe65Nb15B20 ribbon is paramagnetic. The saturation magnetization (M s) decreases with increasing Nb content.