Montmorillonite (MMT) was modified with carboxymethylcellulose (CMC). The X-ray diffraction (XRD) and FTIR analyses showed that the CMC chains had intercalated into the MMT sheets, and the strong chemical interaction between the ether bonds from CMC and Si-O bonds from MMT was the driving force for intercalation. Polyacrylate (PAA)/modified MMT superabsorbent nanocomposites were fabricated by effectively dispersing the modified MMT in acrylic acid solution and polymerizing the acid. The superabsorbent composites were characterized by XRD, TEM, and FTIR. The influence of modified MMT, weight ratio of CMC to MMT, and modified MMT content in the nanocomposites on the water absorbency was investigated. Results showed that the introduction of pure MMT could decrease the water absorbency of the gel, but adding modified MMT could not only effectively increase the water absorbency of the gel, but also improve its water retention ability. (C) 2007 Wiley Periodicals, Inc.