An ethanolamine-assisted route has been designed for one-step synthesis of uniform CuO/Cu2O composite hollow microspheres with controllable composition in an aqueous solution system. The influences of reaction time and temperature on the morphologies and composition of the resulting products were investigated. The content of Cu2O in the composite hollow microspheres ranged from 10 to 84 wt % could be controlled by changing the reaction time and temperature. The formation process for such CuO/Cu2O composite hollow microspheres was studied. The mesoporous CuO/Cu2O composite hollow microspheres exhibited a higher photocatalytic activity for degradation of Rhodamine B under UV-light illumination than the single phase CuO samples. (C) 2012 Elsevier BM. All rights reserved.