application/pdf In the present work we are concerned with the inter-correlation between Bloch walls and structural imperfections in ferromagnetics, both of which are movable under an applied stress. The stress-relaxation accompanied by the movement of lattice imperfections will affect the displacement of Bloch wall. This points to a possibility that a gradual displacement of Bloch walls or their delayed jerkey motion plays an important role in transient creep of ferromagnetics (magneto-elastic relaxation). In fact we have found such a phenomenon in an annealed nickel from the measurements of transient creep without magnetic field in the one case and with field of 400 oersteds in the other, which was performed under the application of very small stresses of the order of 10^6～10^7 dynes/cm^2 at elevated temperatures. Experimental results are discussed somewhat quantitatively from the points of view of the recent theory of boundary layer model concerning mosaic structures in metals in connection with ferromagnetic domain structures. 紀要類(bulletin) 1311195 bytes