This paper presents an investigation of the hydrodynamic behaviour of a gas-solid magnetically stabilized fluidized bed. It consists of spherical steel particles subject to a magnetic field transverse to the gas flow which is created by two permanent magnets. The pressure drop, stability, porosity and expansion are studied. The magnetically expanded bed was found to have many properties similar to a packed bed during the fluidization or in a fluidization-defluidization cycle. It was also found that Ergun's law was in good agreement with experimental results if spherical particles forming chains following field lines are considered as plates.