  We present Vlasov's equation and its association with Poisson's equation in
the context of modelling self-gravitating systems such as Globular Clusters or
Galaxies. We first review the classical hypotheses of the model. We continue
with a presentation of the Hamilton-Morrison structure of Vlasov's equation to
study the equilibrium and the stability of self-gravitating systems. Finally,
we present some preliminary results concerning some properties of the time
dependent solutions of the Vlasov-Poisson system.
