Angular distributions of fragments B, C, N, 0, F, Ne, Na, Mg and Al induced from the reaction of F-19 + Al-27 have been measured at the beam incident energy of 114MeV. The angular distributions and the element distributions at different angles were analyzed to provide an evolution process of the intermediate dinuclear system. The angular dispersion parameters were extracted from the experimental data and compared with the theoretical results. The dynamic dispersions for the dissipative products are not negligible and depend strongly on the charge number Z of the fragments, the deeper dissipation the more dynamic dispersion.