殖民地臺灣的戶口制度，與警察、保甲是密不可分；國勢調查的施行與結果，則是臺灣總督府掌握社會實態的策略之一。由此產生的戶口調查簿與人口資料，財以不同於殖民母國日本的調查項目「種族」，而被社為足以反映日治時代臺灣社會人群現象的重要指標。本文回顧日治時期戶口制度的肇始、變革，發現一九○五年前的「戶口調查」，係以現住人口的掌握與治安控制為主要目的；而針對熟番、生番，則另有調查目的與管道。一九○五年首度實施的國勢調查前身—第一次臨時戶口調查，不但是全島性人口調查的濫殤，並轉化為「戶口規則」，形成配合保甲制度、施行於普通行政區的戶口制度。 殖民地調查增置種族等項目，不但說明日治前期福、客、熟番、生番等人群分類存在的事實，也突顯了臺灣總督府於此一現象的掌握、強化與運用。然而，當臺灣社會歷經不同於傳統農業帝國的殖民統治後，人群關係也同時發生性質的改變。此一歷史轉折，反殃在一九五○年代熟番下傳統族裔身分的集體放棄上；熟番從此藏身劉人世界，直到一九九○年代才重新復甦。 此一跨日治到戰後初期平埔族身份認定過程的釐清與建構，「種族」調查項目在殖民時期的性質，及其與臺灣社會的關係，制度與社會實態之間的接榫與落差，是本文主要探討的面向。

The household registry system of colonial Taiwan was closely associated with the police and ho-k? (poa-chia in Chinese), and the colonial regime utilized the data collected through census as a tool to control Taiwan. This paper traced the origin and transformation of the household registry system in Taiwan under Japanese rule. It was found that household surveys conducted prior to 1905 focused mainly on social control and security. In 1905, the first island-wide census was launched which laid the foundation for the current household registry system. The racial classification employed in the census registry portrayed the social reality of colonial Taiwan. The different radical categories demonstrated not only the co-existence of ethnic varieties, but also the ambitious control of the colonial regime. The 1950s saw the drastic transformation of ethnic identities when the plains Aborigines gave up their original identity and became assimilated the Han Chinese. Only until the 1990s did the Plains Aborigines resume their own ethnic identity. The paper emphasized the context regulating racial classification during the colonial period in order to clarify the issue of postwar identification of Plains Aborigines.