The phases in the compounds (Gd1-xCex)Co2 with x = 0, 0.1, 0.2, 0.3, 0.4, and 0.5 were investigated by X-ray diffraction, and the magneto-caloric effect for x = 0-0.4 was studied by magnetization measurements. The samples are almost single phase with a cubic MgCu2-type structure for x = 0-0.5. The magnetization decreases with an increase in Ce content. There is almost no magnetic transition for x = 0.5 at 100-350 K. The Curie temperature (Tc) of the (Gd1-xCex)Co2 compounds with x from 0.1 to 0.4 are 350, 344, 340, and 338 K respectively. second-order magnetic phase transition in these compounds.