Current‐voltage characteristics were investigated for YBa2Cu3Oy/La1−xCaxMnOzor La1−xSrxMnOz(200 nm)/YBa2Cu3Oyjunctions. The results are discussed together with electrical and magnetic properties of the barrier materials. Supercurrents passed through a 200‐nm‐thick magnetic barrier for certain values ofx. The barrier materials did not necessarily have high electric conductivity in this region, but the ferromagnetism nearly disappeared. The results suggested the possible mechanism of a novel kind of proximity effect concerned with magnetism of the barrier.