An intramolecular electron transfer compound (4-(10-cyano-9-anthracenylmethyl)-NN-dimethylaniline) has been studied under different pressure up to about 6 GPa. The electron transfer (ET) rate constants (k(et)) with pressure have been obtained from its fluorescence emission and decay processes at different pressures. By analogy with the theory of optical transition, the free energy change (DeltaG) and solvent reorganization energy (lambda) during the ET process can be expressed by the functions including the variable pressure. The experimental results can be understood well by analyzing the influence of DeltaG and lambda on the k(et) with pressure. (C) 2003 Elsevier B.V. All rights reserved.