Lightweight composite hollow spheres with conductive and magnetic properties were prepared by using Hollow Glass Spheres (HGS) as substrate. The morphology, composition, conductive, and magnetic properties of the resultant products were characterized by SEM, EDX, XRD, FTIR spectra, conductivity measurement, and vibrating-sample magnetometry. Polyaniline (PANI) were in situ polymerized on HGS with increasing ratios of PANI to HGS, resulting in the enhanced conductivity of HGS/PANI composites from 1.3 x 10(-2) S/cm to 4.4 x 10(-2) S/cm. Lightweight glass/Fe3O4-PANI composite hollow spheres (HGS/Fe3O4-PANI) with conductivity of 5.4 x 10(-3) S/cm and magnetization of 9.25 emu/g were prepared by deposition of Fe3O4 nanoparticles onto HGS via electrostatic adsorption first, and then polymerization of aniline onto HGS/Fe3O4. The glass/PANI-Fe3O4 composite hollow spheres (HGS/PANI-Fe3O4) composed of Fe3O4 as the outmost layer and PANI as the inner layer were prepared for comparison. The conductivity and magnetization of HGS/PANI-Fe3O4 were 1.1 x 10(-4) S/cm and 2.61 emu/g, respectively.