本文嘗試以現行之廿三縣市制為臺灣地區建立日治時期的人口統計，以使戰前和戰後的資料得以銜接一致。行政區域常因各種人為因素而時有分割、合併等重劃調整，因此造成某特定區域之長期人口統計數據在時間上前後紊亂、無法連貫的現象。而此現象素為研究長期人口變遷的一大障礙。以臺灣地區而言，自日治時期以來歷經多次行政區域調整，故歷來相關的研究文獻往往受限於上述現象，而無法呈現人口變遷之長期趨勢。故本文嘗試利用現今所行之兩直轄市與廿一縣市的行政區域架構，透過回溯其相對應區域的各年人口資料，銜接日治時期與戰後時期之人口統計，期有助於一致性人口統計之更長期資料之建立、及相關議題之展開。

Taiwan was a colony of Japan from 1986 through 1945. It has been transforming into a democratic nation after WWII. Consistent statistics on Taiwan's population for the 20th century are unconceivable due to two distinct political regimes using different jurisdiction categories, each of which contains different geographical areas as well as different numbers of lower tiers. The difficulties in integrating the pre-war and post-war sets of data into a single system are tedious and formidable. Yet integrated population statistics at the sub-provincial layer across two regimes have been advanced in this work. By carefully and appropriately converting the geographical area associated with the population of every local jurisdiction during the period of Japanese governance into the current categories of administrative jurisdiction, we offer the possibility of setting up a century long set of population statistics. The results will facilitate a number of long term studies on Taiwan in the future.