Magnetic polymer composites were synthesized via suspension polymerization method, incorporating nanoFe3O4 powder into poly (methyl methacrylate) (PMMA) and polystyrene (PS) matrices in order to obtain polymer magnetic microspheres with perspectives in sensing applications. The monomer (MMA or Styrene) and the magnetic powder (pre-made Fe3O4, 20nm in diameter) are mixed together under vigorous stirring and follows suspension polymerization. The product was sequentially filtered through a range of sieves and spherical composites were obtained with grains of sizes ranging from 45μm to 250μm. The yield of polymerization was 60% to 85% for the two different matrices in samples and the corresponding polymer product contained 1.25wt% to 4.00wt% of Fe3O4. It is observed that increasing the content of magnetite affect the surface morphology of the microspheres and their magnetic behavior. The pure nanoFe3O4 powder and the magnetic polymer microspheres were characterized using techniques such as X-Ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), optical microscopy and magnetization measurements carried out by a Vibrating Sample Magnetometer (VSM) .