Magnetizable bed structures are discussed with respect to fixed-, intermediate- and fluidized-bed states. Magnetic intermediate- and fixed-bed structures depend on defluidization paths, with the magnetic alignment of particles being maintained by the field as fluid velocity is diminished. Data are provided of experimental versus theoretical pressure drop, and superficial velocities are reported that provide information in the form of increased effective porosities which reflect the magnetic structural changes. Major and minor magnetic structural hysteresis phenomena are defined and options of using alternating bed structures are discussed. The effect of field gradients on fluidized beds, and implications of bed structures regarding potential use for particle processing and magnetic separation are also considered.