A　second　order　almost　periodic　perturbed　nonlinear　system　with　small　parameter　is　discussed　in　this　paper.　Based　on　some　analytical　techniques　and　the　method　of　averaging,　some　sufficient　conditions　are　obtained　for　existence　of　one　almost　periodic　solution.　Also　some　suitable　conditions　are　given　for　existence　of　two　almost　periodic　solutions.　The　obtained　new　results　generalized　the　known　results　in　Seifert　[1,3]　and　He　[2,4]　Finally,　some　applications　are　presented　to　illustrate　that　our　results　are　a　good　generalization　of　the　known　results　(C)　2009　Elsevier　B　V.　All　rights　reserved