Konjac glucomannan acrylates (KGM-AA) were used as soft templates to prepare the CdS nanoparticles. The structure and properties of the CdS nanoparticles were characterized and evaluated with XRD, TEM, HRTEM, TGA, UV-vis, Raman spectrum, optical limiting and nonlinear optical analyses (Z-scan technique), respectively. It was interesting to find that nanosized CdS particles successfully grew in situ and uniformly dispersed in the KGM-AA soft templates and their size and density could be effectively controlled by varying the feed ratio of Cd2+/KGM-AA. When the feed ratio is up to 17.47% (wt%), the material exhibits the best optical limiting performance with limiting threshold of 367 mJ/cm(2), and good nonlinear optical properties with nonlinear absorption coefficient (alpha(2)) of 6.6023 x 10(-10) cm W-1 and nonlinear refractive index (n(2)) of 1.27 x 10(-4) cm(2)/GW. The optical limiting performances increase with the increase of CdS content in the composites. The optical limiting mechanism is mainly originated from the self-focusing behavior of CdS nanoparticles. (C) 2013 Elsevier Ltd. All rights reserved.