2005-Oujda International Conference on Nonlinear Analysis, Oujda, Morocco. Electronic Journal of Differential Equations, Conference 14 (2006), pp. 109-117. Title: Nonresonance conditions for a semilinear wave equation in one space dimension Authors: Aomar Anane (Univ. Mohammed 1er, Oujda, Maroc) Omar Chakrone (Univ. Mohammed 1er, Oujda, Maroc) Abdellah Zerouali (Univ. Mohammed 1er, Oujda, Maroc) Abstract: In this paper we study the existence of periodic weak solutions for semilinear wave equations in one space dimension in the case of nonresonance. Published September 20, 2006. Math Subject Classifications: 35J65, 35J25. Key Words: D'Alembertian; homotopy argument; eigenvalues.