Fine Fe3O4 particles with mean size of 200 nm were synthesized by coprecipitation and drying, and then hybridized in air with nylon and polyethylene particles having a mean size of 10 and 5 mum, respectively. Particle features and their corresponding magnetic properties were investigated. Fine Fe3O4 particles were successfully coated onto nylon and polyethylene particles with microstructures dependent on the mixing ratio. Fine Fe3O4 particles exhibited no structural change or particle growth and retained their magnetic properties after hybridization. (C) 2003 Elsevier B.V. All rights reserved.