We propose a novel dynamic exciton expression based on the quantum master equation approach using the ab initio molecular orbital (MO) singly excited configuration interaction (CI) method developed in our previous paper [M. Nakano, M. Takahata, S. Yamada, R. Kishi, T. Nitta, K. Yamaguchi, J. Chem. Phys. 120 (2004) 2359]. This expression is derived from the partition of polarization density in the configuration basis into the electron and hole contributions, and can describe both the coherent and incoherent dynamics of electron and hole density distributions, e.g., dynamic electric polarization, exciton recurrence and exciton migration.