In this article, we reported a facile and effective strategy for assembling hybrid ZnAl-layered double hydroxide/carbon nanotubes (ZnAl-LDH/CNTs) nanocomposites through noncovalent bonds, for the first time, in the presence Of L-cysteine molecules. The materials have been characterized by powder X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), thermogravimetry and differential scanning calorimetry (TG-DSC), X-ray photoelectron spectra (XPS) and specific surface area measurement. The results indicate that L-cysteine as bridging linker plays a key role for enhancing both adhesion and dispersion of LDH nanocrystallites onto the surface of CNTs matrix through the interfacial interaction, and effectively inhibits the in situ growth of LDH crystallites, thus resulting in remarkably reduced LDH crystallite sizes; the Eu(III) fluorescence quenching in intercalated-Eu(III)complex LDH/CNTs nanocomposite can occur because of the interaction between LDH crystallites and CNTs matrix. Furthermore, it is found that as-assembled hybrid LDH/CNTs nanocomposites exhibit excellent performance for photodegradation of methyl orange molecules under UV irradiation, which is closely related to the unique hybrid nanostructure and composition of composites. (C) 2009 American Institute of Chemical Engineers AIChE J, 56: 768-778, 2010