Different Mg-Al layered double hydroxide (LDH) 3D micro-nano structures had been synthesized via a facile solvothermal method. By carefully controlling the fundamental experimental parameters, the morphologies of hexagonal nanoplates, rose-like micro-nano structures, chrysanthemum-like micro-nano structures, and spherical micro-nano structures have been efficiently obtained, respectively. And these micro-nano structures are formed from self-assembly of nanoplates in a spontaneous process in solvothermal system. It is also found that the concentration of the reactant and the dosage of CTAB have significant effects on the morphology of the products. The FT-IR spectra and thermal stability of the micro-nano structures were explored. (C) 2011 Elsevier Ltd. All rights reserved.