Abstract: The temperature dependences of magnetic properties and magnetic field behavior of Co/Gd/Co thin-film three-layer systems obtained via ion-plasma magnetron sputtering are studied. The thickness of cobalt layers is 5.0 nm and of Gd layers (tGd) varies from 3.0 to 10.0 nm. The bulk magnetic characteristics of the samples were measured on a vibration magnetometer with an external magnetic field oriented parallel to the plane of the samples. The influence of the temperature and the thickness of a Gd layer on the shape of the hysteresis loops, the values of the magnetic moment m and the coercive force HC are discovered. In particular, when the temperature changes from 100 to 300 K, the coercive force decreases, and the magnetic moment increases at a temperature above 150 K. The m value decreases with an increase in thickness of gadolinium.