Three-dimensional brush-like ZnO-TiO2 hierarchical heterojunctions nanofibers have been successfully obtained by the combination of the electrospinning and hydrothermal process. The FESEM images showed that the brush-like ZnO-TiO2 hierarchical heterojunctions nanofibers are composed of uniform ZnO nanorods layer of approximately 100-300 nm in diameter grown on the side surface of TiO2 core nanofibers. The gas sensing studies revealed that the ZnO-TiO2 sensors exhibited enhanced sensing performance to ethanol compared with the pristine TiO2 nanofibers and pristine ZnO nanorods, which might be attributed to the unique hierarchical structure and great degree of electron depletion of the interface based on the synergistic effect among the two components of TiO2 and ZnO. (c) 2013 Elsevier B.V. All rights reserved.