Graphene oxide wrapped alumina (GO/Al2O3) composites were synthesized by a facile titration method using Al2O3 colloid as a titrant. The positively-charged Al2O3 particles were prepared by adjusting the pH, followed by wrapping with negative GO particles via electrostatic attractions. Scanning electron microscopy and transmission electron microscopy confirmed that the Al2O3 particles were wrapped completely with homogeneous GO sheets, and Fourier transform infrared spectroscopy provided evidence of the coexistence of GO and Al2O3 in the composites. The resulting GO/Al 2O3 composites exhibited electrorheological (ER) properties when dispersed in silicone oil, highlighting the potential engineering applications for GO/metal oxide systems. © 2014 Elsevier B.V.