Under some conditions on the functional perturbation Φ (t1, yt), we the asymptotic relationshiop between solutions of the perturbed equation and of the linear ordinary equation. We also discuss the same problem of equations. For equations (2) and (4), we assume that te general solutions and their asymptotic beha-vior are known. An integral inequality of Bellman-Gronwall-Bihari type is used. Our conclusions generalize the Theorem 7 in [1] and Theorems 1, 2 in [2].