Open problems in formation and decay of composite systems in heavy ion reactions

New highly exclusive experiments in the field of formation and decay of com posite systems in heavy ion reactions are presented, Dynamical effects are reviewed in the light of recent works on the role of the N/Z asymmetry betw een projectile and target. the possibility of extracting directly from the experimental data the emission barrier of alpha particles emitted from high ly excited nuclei is discussed. Finally, the first experimental evidence of double giant resonance excitation in fusion-evaporation reaction is presen ted.