Fluorescence dynamics of a cyanine dye, 3,3'-di(3-sulfopropyl)-thiacyanine triethylaminium salt, encapsulated by beta-cyclodextrin was investigated by femtosecond fluorescence time-resolved up-conversion technique. The quickening up of the fluorescence decay was found in comparison with the fluorescence dynamics of the dye in water. This phenomenon may be a good experimental support for the expanded BFO theory with two-dimensional excited potential surface.