Gd-Co alloy films were synthesized by potentiostatic electrolysis on Cu substrates in urea-acetamide-NaBr-KBr melt at 353 K. The elec- troreduction of Co2+ and Gd3+ was investigated by cyclic voltammetry. The reduction of Co2+ is an irreversible process. Gd3+ cannot be re- duced alone, but it can be inductively co-deposited with Co2+. Both the Gd content and microstructure of the prepared Gd-Co alloy films can be controlled by the deposited potential. The content of Gd was analyzed using an inductively coupled plasma emission spectrometer (ICPES), and the microstructure was observed by scanning electron micrograph (SEM). The films were crystallized by heat-treatment at 823 K for 30 s in Ar atmosphere, and then were investigated by XRD. The hysteresis loops of the Gd-Co alloy films were measured by a vibrat- ing sample magnetometer (VSM). The experimental results reveal that the deposited Gd-Co alloy films are amorphous, while the annealing causes the samples to change from amorphous to polycrystalline, thus enhancing their magnetocrystalline anisotropy and coercivity. More- over, the magnetic properties of the Gd-Co alloy films depend strongly on the Gd content. Gd-Co alloy films were synthesized by potentiostatic electrolysis on Cu substrates in urea-acetamide-NaBr-KBr melt at 353 K. The elec- troreduction of Co2 + and Gd3 + was investigated by cyclic voltammetry. The reduction of Co2 + is an irreversible process. Gd3 + Both the Gd content and microstructure of the prepared Gd-Co alloy films can be controlled by the deposited potential. The content of Gd was analyzed using an inductively coupled The lenses were crystallized by heat-treatment at 823 K for 30 s in Ar atmosphere, and then were investigated by XRD. The hysteresis loops of the Gd-Co alloy films were measured by a vibrating-sample magnetometer (VSM). The experimental results reveal that the deposited Gd-Co alloy films are amorphous, while the annealing causes the samples to change from amorphous to polycrystalline, thus enhancing their magnetocrystalline anisotropy and coercivity. More- over, the magnetic properties of the Gd-Co alloy films depend strongly on the Gd content.