In this paper we investigate the problem of existence and asymptotic behavior of solutions for the nonlinear boundary value problem $$ϵy^{\text{'}\text{'}}+ky=f(t,y),t\in \langle a,b\rangle ,k<0,0<ϵ\ll 1$$ satisfying three point boundary conditions. Our analysis relies on the method of lower and upper solutions and delicate estimations.