Europium ternary complex of Eu(NNA)(3)(.)phen (NNA = alpha-naphthylacetic acid and phen = 1,10-phenanthroline) was incorporated in silica matrix with different ratio by sol-gel method. The luminescence properties of the silica composites were studied by comparing with the corresponding pure complex with the approaches of excitation, emission spectra and lifetimes. The results indicate that the hybrid complexes show fewer emission lines and weaker fluorescence intensity than that of the pure complex. The fluorescence lifetime was prolonged when the pure complex was incorporated in silica matrix. The fluorescent relative intensity and fluorescence lifetimes increased simultaneous with the content of Eu(NNA)(3)(.)phen increasing. (C) 2002 Elsevier Science B.V. All rights reserved.