[en] This manuscript corresponds to four lectures at the Summer School of ''Predeal'' in Rumania (september 1978). In a first part, the present status of the main theoretical approaches of Deep Inelastic Reactions between Heavy Ions is described as follow: brief survey of the main characteristics of these reactions, the classical phenomenological equation of motion and the diffusion model and finally the unified theory for Energy Dissipation and Fluctuations. The second part deals with two aspects of experimental results which have been emphasized recently. 1) De-excitation of the fragments by light particle emission (neutrons, protons and alpha particles), 2) Experimental attempts in order to evaluate the transfer of angular momentum into intrinsic spin of the fragments