In order to improve its dispersibility and preserve its activity, nano-aluminum was encapsulated with poly(trimethylolpropane triacrylate) (PTMPTA) by in situ solution polymerization. The affecting factors of the conversion of monomer (CM), percentage of grafting (PG) and grafting efficiency (GE) were systematically studied. It was found that nano-aluminum had been evenly encapsulated with a layer of PTMPTA through chemical bond. And PTMPTA/Al nanocomposite particle with core-shell structure had been successfully synthesized. Compared to that of nano-aluminum, the dispersibility, corrosion resistance, thermal stability, especially the activity preservation (when it was used as additive in solid rocket propellants) of composite particle had been markedly improved. (c) 2008 Elsevier B.V. All rights reserved.