Excitation energy transfer in a symmetric dimer embedded in biomolecular environment is theoretically analyzed. The present study especially focuses on the role played by conformational oscillation of surrounding environment, which may cause the oscillation of electronic coupling relevant to energy transfer. A generalized master equation describing the temporal evolution of population densities of exciton is derived from the quantum Liouville equation for density matrix, and solved with a memory function representing the relaxational and oscillatory features of temporal correlation of electronic coupling. Modulations of the coherent dynamics of excitation energy transfer are thus discussed analytically and numerically. (C) 2011 Elsevier B.V. All rights reserved.