Three-dimensional boxlike microstructures' assembled from 1D-nanofibers of polyaniline (PANI) were synthesized by a template-free method in the presence of perfluorosebacic acid (PFSEA) as the dopant for the first time. The 3D-boxlike microstructures show both super-hydrophobic and high-crystalline properties. The trick of forming such complex micro/nanostructures is that the PFSEA not only serves as both dopant and soft-template, but also provides hydrogen bond and hydrophobic interactions as driving forces for self-assembly from 1D-nanofibers to 3D-boxlike microstructures due to low-surface energy perfluorinated carbon chain and two hydrophilic -COOH end groups. (c) 2008 Elsevier Ltd. All rights reserved.