In the present paper, the authors studied the effects of KCl on the fluorescence of [Ru(bpy)3]2+ solution containing silver nanoparticles by UV-Vis absorption spectra and fluorescence spectra. The results indicated that the stronger action between KCl and silver nanoparticles led to the vanishing of chain-like net structure formed between [Ru(bpy)3]2+ and silver nanoparticles and the formation of large particles and aggregates in the solution. Meanwhile, a new band at longer wavelength region appeared and the peak at long wavelength was red-shifted and broadened with the increase of KCl. With the increase in KCl content, the fluorescence decreases first and then increases till a constant value. The authors discussed the mechanism of the effects KCl on the fluorescence of [Ru(bpy)3]2+ solution containing silver nanoparticles in terms of interaction and energy transfer.