Points de hauteur bornee sur les varietes de drapeaux en caracteristique finie

The aim of this paper is to apply the work of Morris on Eisenstein series over global function fields to the study of the asymptotic behavior of the points of bounded height on a generalized flag variety defined as the quotient of a semi-simple algebraic group by a reduced parabolic subgroup over such a field. The formula obtained for the height zeta function has an interpretation similar to the one known over a number field.