  To explore the roles of dynamical model and statistical model in the
description of multifragmentation in heavy-ion collisions at intermediate
energies, the fragments charge distributions of $^{197}$Au+$^{197}$Au at 35
MeV/u are analyzed by using the hybrid model of improved quantum molecular
dynamics (ImQMD) model plus the statistical model GEMINI. We find that, the
ImQMD model can well describe the charge distributions of fragments produced in
central and semi-central collisions. But for the peripheral collisions of Au+Au
at 35 MeV/u, the statistical model is required at the end of the ImQMD
simulations for the better description of the charge distribution of fragments.
By using the hybrid model of ImQMD+GEMINI, the fragment charge distribution of
Au+Au at 35 MeV/u can be reproduced reasonably well. The time evolution of the
excitation energies of primary fragments is simultaneously investigated.
