Abstract: Novel bichromophoric rhodamine dyes,in which carbazole chromophore was connected with rhodamine 6G or rhodamine DR-21 by -CH₂CH₂-,have been synthesized.The absorption and fluorescence spectra of these bichromophoric dyes have been measured. The absorption of the bichromophoric dyes is the sum of that of two chromophores alone.A lot of fluorescence emission of carbazole in the bichromophoric dyes was quenched. The fluorescence lifetimes of the dyes have been measured by single-photon counting technique. The fluorescence lifetime of carbazole is shortened obviously in the bichromophoric dyes(from 15.4 ns reduced to about 7.8ns). The intramolecular energy transfer and charge transfer between two chromophores have been discussed.

Key words: fluorescence lifetime, energy transfer, multi-chromophoric dyes