The density matrix and the transient linear susceptibility theories are used to calculate the fluorescence depletion spectrum and the internal conversion (IQ time of chlorophyll-a (Chl-a) in ethyl acetate solvent. The IC time and the vibrational relaxation time of Chl-a in the ethyl acetate solvent are 133 fs and 1.5 ps at room temperature, respectively. The calculated fluorescence depletion spectrum of Chl-a in the ethyl acetate solvent agrees well with the experimental result of Shi et al. [Shi et al.,Chem. Phys. Lett. 410 (2005) 260]. The effects of solvation and the IC time on the fluorescence depletion spectrum are also discussed. (c) 2006 Elsevier B.V. All rights reserved.