The initial value problem for a small disturbance from an equilibrium of an encounterless stellar system is discussed. In a spherical cluster small wave-length disturbances damp as the stars become well mixed. In the artificial infinite uniform rotating system we discuss disturbances of all wave4engths. Jeans' condensational instability is the same as in a coffision dominated gas. Landau damping occurs for wave-lengths smaller than the critical one.