Graphene-Fe3O4 micro-nano scaled hybrid spheres with the diameter of similar to 100 nm were fabricated via solvent-thermal route, which combined the hybridization growth of Fe3O4 nanoparticles and graphene oxide in one single step. The hybrid spheres showed a homogenous phase without obviously interfaces between graphene and Fe3O4. Owing to the interfacial polarization and good separation of magnetic properties, the interpenetrating constitution of the materials brought good synergistic effects on the electromagnetic wave absorbing properties: a multi-frequency reflection band covered C-band and Ku-band with maximum reflection loss -20 dB as the matching thickness of 5 mm gave very promising desire for lightweight and strong electromagnetic attenuation applications. (C) 2013 Elsevier Ltd. All rights reserved.