We have performed femtosecond time‐resolved fluorescence spectroscopy up to 10 ns for a dye molecule in a alcohol mixture at 170 K and 296 K. It has been found that the energy relaxation occurs in the electronic excited state of the molecule owing to the structural dynamics of the surroundings of the molecule with time constants of the order of 0.1 ps, 1 ps and a slower one, and the temperature dependence of it implies that there is some connection among the relaxation components with different time constants. © 2004 American Institute of Physics