The SmCo3.1−xFe0.9CuxB (x = 0, 0.02, 0.06 and 0.1) ribbons were prepared by melt-spinning at 40 m/s accompanied by annealing at 800 °C for 30 min, and then their structures and magnetic properties were investigated. The results show that the annealed ribbons are composed of single Sm(Co,Fe)4B phase at x = 0, and single Sm(Co,Fe,Cu)4B phase at x = 0.02–0.1. These phases with different Cu contents have the same hexagonal CeCo4B-type structure with a space group of P6/mmm, and the lattice parameters a and c increase monotonically with increasing x from 0 to 0.1, while the axial ratio of c/a remains almost unchanged (c/a = 1.3495). In particular, the x = 0.06 ribbons consisting of short rod-shaped Sm(Co,Fe,Cu)4B grains, which contact with each other directly, show the high coercivity of up to 44450.0 Oe, and each in-plane grain exhibits preferred orientation along its long or short axis direction.