SiO2 nanoparticles with eight different concentrations were doped in the Rhodanmine 6Gethanol solutions(3×10－4 M and 1×10－4 M).The influence of SiO2 nanoparticles to the fluorescence spectra of R6Gethanol solutions were investigated. The results shows:1)when the concentrations of SiO2 within in the range of n1～n4(1012～1010/mL), the fluorescence spectra at 549 nm were well enhanced, but the fluorescence peaks at 570 nm was obviously quenched and the peaks have a read shift; 2) when the concentrations of SiO2 within in the range of n5～n8(109~107/mL),the fluorescence spectra at 549 nm were not enhanced significantly, but the fluorescence peaks at 570 nm was obviously enhanced, the enhancement factors can get to 10%~20%, and the peaks do not have a red shift. The reasons of the fluorescence enhancing or quenching are relative to the scattering of the nanoparticles to the luminescence and the nonfluorescent Hdimers or fluorescent Jdimers of R6G moleculars.