The effects of high magnetic fields on the migration and rotation of TiAl3 particles in an Al-7 wt.% Si alloy were studied. Without magnetic fields, the rod-like TiAl3 particles segregate at the lower part of the solidified structure. Under high uniform magnetic fields, these particles rotate to an orientation with their longitudinal axes parallel to the direction of the magnetic flux. The segregation of the particles reduces with the increase of the magnetic flux density. A negative gradient field enhances the effect of the uniform magnetic field. By altering high magnetic fields, Al-Si alloy samples containing homogeneously distributed and preferably aligned TiAl3 particles were prepared.