A series polyacrylamide/Na-montmorillonite nanocomposites was prepared by in situ free radical polymerization in aqueous medium using benzoyl peroxide (Bz(2)O(2)) as a radical initiator. To characterize the resultant nanocomposites, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and thermogravimetric analysis techniques were used. The moisture retain, water uptake, antibacterial properties, BET specific surface area and specific nanopore volume of nanocomposites were determined. The X-ray diffraction pattern showed that the polyacrylamide was intercalated up to 60.0 mass% acrylamide concentration, and then montmorillonite layers exfoliated into the polyacrylamide matrix. The interlayer spacing (d(001)) of the montmorillonite increased from 1.19 to 1.90nm by intercalation. Transmission electron microscopy views showed that the Na-montmorillonite partially exfoliated in polyacrylamide. The nanocomposites exhibited better thermal stability than the pure polyacrylamide.