In　this　study,　the　ground　motions　that　can　be　attributed　to　the　aftershocks　of　the　2008　Mw7.9　Wenchuan,　China　earthquake　recorded　in　the　Wudu　basin,　which　is　a　small　basin　in　the　eastern　Tibetan　Plateau,　are　analyzed　to　investigate　the　seismic　effect　of　a　small　sedimentary　basin.　In　case　of　the　Wudu　basin,　the　site　responses　from　the　basin　edge　are　stronger　than　those　from　the　basin　center,　the　monitoring　sites　located　near　the　Wudu　basin　edge　and　the　Wudu　basin　center　are　sensitive　to　the　low-frequency　(　＜　3　Hz)　and　high-frequency　(　＞　5　Hz)　components　of　ground　motion,　respectively.　It　indicates　that　some　different　seismic　phenomena　occurred　in　a　small　sedimentary　basin　compared　with　a　large　sedimentary　basin.　To　further　study　the　ground　motion　in　a　small　sedimentary　basin,　a　simulation　of　the　Wudu　basin　was　conducted　using　the　finite　element　method　with　a　viscous-elastic　artificial　boundary.　The　grid　size　of　the　surface　layer　of　the　basin　is　2.5　x　2.5　m(2),　and　high-frequency　(up　to　10　Hz)　components　of　a　synthetic　waveform　were　obtained.　The　simulation　denoted　that　the　surface　wave　initially　appeared　in　the　Wudu　basin　edge　and　subsequently　propagated　into　its　interior.　The　near-surface　soil　layers,　exhibiting　a　relatively　low　wave　velocity,　magnified　the　amplitude　of　the　seismic　wave　in　the　Wudu　basin.　Furthermore,　the　numerical　simulation　results　are　basically　consistent　with　the　actual　ground　motion　records,　especially　with　the　same　predominant　frequencies　of　ground　motions　at　the　sites　located　near　the　Wudu　basin　edge.