平埔族群的主權議題隨著正名運動的發展，逐漸浮現。「平埔族」或「熟番」因為與漢人接觸較早，土地權的流失以及深度的「漢化」，主權內涵的強調必須和其他原住民族區分開來。本文將嘗試從另一個角度切入：從台灣平埔原住民族正名運動團體挖掘出台灣省政府因行政疏失，以致於平埔族喪失登記為「平地山胞」的機會，並據以要求恢復身分而遭原民會拒絕這一個背景談起。在討論這個爭論之前，先簡單勾勒清代已降不同階段的政府在「熟番」這個分類項目認定上的差異，這些差異和政治的考量密不可分，國民政府在繼承了過去的分類範疇，卻又對內涵無知的情況下，導致行政疏失（從省政府的函令漏掉台南縣及宜蘭縣即可看出）。第三部分將討論平埔族群在爭取主權時所必須面對的內部認同與外部承認（認定）的雙重難題。最後一部分將回到主權問題，強調平埔族群主權議題上應著重於文化權。

As the recognition movement of the unrecognized plains indigenous developed, the issue of the sovereignty was emerging gradually. The study bases on the case of the administrative negligence of Taiwan’s Provincial Government to investigate why the unrecognized plains indigenous peoples lost the opportunities of identity registration. Before discussing the controversy, the author explained the different of the indigenous identity from Qing Dynasty to KMT Government. Furthermore, the author thought if the unrecognized plains indigenous peoples want to confirm their sovereignty, they would face the challenges of internal identity and external identity. Lastly, the author proposed the issue of sovereignty should focus on the cultural rights.