The tendency of some copper–nickel-based ternary alloys with additions of 3d transition metals, such as Cr, V, and Fe, to oxidation has been studied. The resistance to the oxidation was evaluated by the thermogravimetry method. It has been established that the strengthened textured tapes made of the Cu–40% Ni–1.2% Cr and Cu–40% Ni–1.4% Fe alloys have significantly better anticorrosive properties at 700°C than tapes made of pure copper and other investigated alloys, and can be used as substrates for epitaxial deposition of buffer and superconducting layers at elevated temperatures.