Cu-Mn-Dy resistive thin films were prepared on glass and Al2O3 substrates, which was achieved by co-sputtering the Cu-Mn alloy and dysprosium targets. The effects of the addition of dysprosium on the electrical properties and microstructures of annealed Cu-Mn alloy films were investigated. The composition, microstructural and phase evolution of Cu-Mn-Dy films were characterized using field emission scanning electron microscopy, transmission electron microscopy and X-ray diffraction. All Cu-Mn-Dy films showed an amorphous structure when the annealing temperature was set at 300 degrees C. After the annealing temperature was increased to 350 degrees C, the MnO and Cu phases had a significant presence in the Cu-Mn films. However, no MnO phases were observed in Cu-Mn-Dy films at 350 degrees C. Even Cu-Mn-Dy films annealed at 450 degrees C showed no MnO phases. This is because Dy addition can suppress MnO formation. Cu-Mn alloy films with 40% dysprosium addition that were annealed at 300 degrees C exhibited a higher resistivity of 2100 cm with a temperature coefficient of resistance of -85 ppm/degrees C.