The solidified structure of solute elements is important for the quality and the properties of alloys. In the present study, the solidification behavior of aluminum alloys is studied under various high magnetic field conditions, and the influences of uniform and gradient magnetic fields with different intensities and directions on the distribution and the morphology of solute elements of Al-Cu and Al-Mg alloys are investigated. It is found that because of the difference in the electromagnetic forces acting on Cu element and Mg element which have different physical properties in the matrix, the distributions of Cu element and Mg element are the opposite both in the matrix crystallites and in grain boundaries under high static magnetic field, and not only the content but also the distributions of Cu and Mg elements are obviously different under gradient magnetic field. This paper offers a reference to control the solidification structure of solute elements whose physical properties are different in alloys under high magnetic fields.