The Mg_xNi_1-xMn₂O₄(MNM x=0, 0.05, 0.10, 0.15, 0.20) films were grown on Al₂O₃ substrate by chemical solution deposition method. The effect of Mg doping on the structural properties of MNM thin films was studied by x-ray diffraction and field emission scanning electron microscopy. The results show that the films have a single cubic spinel structure and the films aresmooth and uniform, which have good crystallinity. The electrical measurements show that the conduction of MNM thin films was described by a variable range hopping model. The values of resistivity, characteristic temperature T₀, negative resistance temperature coefficient α for MNM thin films were obtained. The Mg concentration dependence of structural and electrical properties for MNM films was investigated.