We report here the study of different peripherally modified palladium phthalocyanine (PdPc) encapsulated in silica gel glass obtained by sol-gel technique. The resulted composites were transparent and homogeneous with required optical limiting properties. Trapping effect was checked by UV/Vis absorption spectra and pore structure of the composites. Optical limiting properties were measured at 532 nm with 8 ns pulses. The results show that all the PdPcs have better optical limiting effect in composite than in solution, among which, PdPc-C has the best optical limiting effect due to its largest peripheral substituent. (C) 2004 Elsevier B.V. All rights reserved.