The aim of this work is to create a biocompatible superparamagnetic nanocomposite applicable as vehicle for magnetically guided drug delivery. Both materials, the nanostructured silicon as well as the iron oxide nanoparticles offer low toxicity. Therefore Fe3O4-nanoparticles have been incorporated within nanostructured silicon. The iron oxide nanoparticles have been synthesized in solution and then were either filled in or chemically grown within the pores. The magnetic properties of the system have been optimized concerning the blocking temperature TB and the magnetic moment M, which are conflicting parameters. A particle size/distance and template dependent assessment of the magnetic properties of the nanocomposite will be presented. Although the growth of iron oxide particles within the porous template is not easy to control, the blocking temperature of the composite could be achieved far below room temperature.