The change in the interface profile between immiscible nonmagnetic liquids was investigated quantitatively in a superconducting magnet with a large horizontal bore. The interface profile changed into concave down or up at the field center accordingly to the balance of magnetic susceptibilities between the lower and upper liquids. A flat interface was also demonstrated when the susceptibilities were balanced. It was found that modification of the interface profile was significantly amplified under an applied field as low as 1 T when the densities of the two liquids were quite close. The morphological change induced by the applied magnetic field can be used to remove a boundary, which initially separates two liquids without the held, and to initiate a mixing process or a chemical reaction between the two liquids. (C) 1996 American Institute of Physics.