A novel nanostructured magnetic composite materials for solid base catalyst composed of CoFe2O4 as the magnetic core and magnesium aluminum layered double hydroxide with OH- as interlayer anion (abbreviated as MgAl-OH-LDH) providing basic sites has been achieved. The catalyst has been characterized using XRD, IR, TG-DTA, BET, TEM, XPS, VSM and PSD analysis techniques, and evaluated by self-condensation of acetone. The results manifest that a MgAl-OH-LDH Bronsted base catalytic layer coats onto the surface of a magnetic core CoFe2O4 through Mg-O-Co(Fe) and/or Al-O-Co(Fe) linkage with particle size dristribution in the range of 38-126 nm, and the catalyst acts high catalytic activity and selectivity in self-condensation of acetone. The diacetone alcohol conversion reaches 15.3% at 273 K. After easily recovery through an exterior magnetic field, high recovery rate of MgAl-OH-LDH/CoFe2O4 (98%) is gained, and high activity (14.1% and 13.6%) has still remained in the same two reactions. (C) 2008 Elsevier B.V. All rights reserved.