清代臺灣缺乏完整的人口普查數據，甚至於苦於偷渡猖獗，亦不可能求得完整的數據，但它所留下來的官方紀錄，仍具有參考價值。因為在歷史研究上，它代表二層意義：其一，清廷在規劃臺灣駐軍時，必定以掌握的人口數字為根據，然後再決定各汛塘的地點與兵力人數。其二，從人口成長的數字，顯示出臺灣綠營一萬餘名的兵力，決不可能單獨控制超過它數百倍以上的人口。針對如此的窘境，清廷必須在綠營之外，還需要設想更好的武力統治策略。 透過本文的研究，發覺清代臺灣的人口數據分成三種。第一是所謂「帳面上」的人口，即是丁額的財政收稅人口。第二是所謂「認知上」的人口，則是從1740年開始進行人口編審的數字。其三是所謂「預計上」的人口，實為從鹽額估算出來的人口。透過這三種數字的討論，證明在清代官僚體制之下，官方對於人口數據的掌握，仍有一定程度的用心。而這也是清廷力求，穩定治臺前題下的必要保證。

The complete population census data is lacking for Taiwan during Qing Dynasty, given illegal immigration (from China across Taiwan Strait) ,accurate retrospective estimate of this data is also impossible. Despite this, the official records can still provide insights. There are two implications that can derive from those records. Firstly, it was certain that the Qing court must have fairly accurate information about the population as the basis to plan its distribution of military strength and distribution of its garrisons. Secondarily, it was not possible to effectively control the population several hundreds times larger with just ten thousand strong soldiers. The Qing court must have devised even better strategies to rule other than solely relied on the military presence. According this research, I discover that there are three types of Taiwanese population record during the Qing Dynasty. The first one is called 「accounted population」. This is the population size used for taxation purposes. The second one is called」acknowledged population」. It is data derived from population census from 1740 and subsequent years. The third one is called「estimated population」. It is a population estimate derived from amount of salt consumed. I prove that the Qing government did have a good grasp about the true population size based on these three records of Taiwan population. Indeed, theses are the foundations for Qing court’s stable rule on this island.