Anisotropy of the fluorescence spectrum of 1,2,4,5-tetrametoxybenzene (TEMB) in EPA matrix at 77 K showed a wavelength dependence indicating that the fluorescence was consisted of two components. This dual fluorescence can be explained by a modification of the S-1(B-2u) --> S-0(Ag) transition moment of TEMB through the coupling with a synchronous in-plane or out-of-plane bending motion of the methoxyl groups.