Abstract: A class of singularly perturbed boundary value problems for semilinear equations of fourth order with two parameters are considered. Under suitable conditions, using the method of lower and upper solutions, the existence and the asymptotic behavior of the solution to the boundary value problem are studied. In the present paper, the solution to the original singularly perturbed problem with two parameters has only one boundary layer.

Key words: nonlinear, two parameters, singular perturbation, lower and upper solutions