Abstract. Let H be the fixed point group of a rational involution σ of a reductive p-adic group on a field of characteristic different from 2. Let P be a σ-parabolic subgroup of G i.e. such that σ(P ) is opposite to P . We denote the intersection P ∩ σ(P ) by M . Kato and Takano on one hand, Lagier on the other hand associated canonically to an H-form, i.e. an H-fixed linear form, ξ, on a smooth admissible G-module, V , a linear form on the Jacquet module j P (V ) of V along P which is fixed by M ∩ H. We call this operation constant term of H-forms. This constant term is linked to the asymptotic behaviour of the generalized coefficients with respect to ξ.P. Blanc and the second author defined a family of H-forms on certain parabolically induced representations, associated to an M ∩ H-form, η, on the space of the inducing representation. The purpose of this article is to describe the constant term of these H-forms.Also it is shown that when η is discrete, i.e. when the generalized coefficients of η are square integrable modulo the center, the corresponding family of H-forms on the induced representations is a family of tempered, in a suitable sense, of H-forms. A formula for the constant term of Eisenstein integrals is given.