Based on historical documents and census data, this research examines the processes and characteristics of population growth and demographic change in Lu Tao since ethnic Chinese settled the island in late 18th century. A summary of findings of the research is as follows: 1. In the beginning of the 19th century, ethnic Chinese from Liuchiu Yu, originating from Hsen Feng,Fukien Province,started to migrated to the island. By the end of Chuan chou, limited arable land on the island had all been settled by the immigrants. At around 1895, the beginning of Japanese colonial rule, there were around 120 to 130 immigrant households, around 500 to 600 people that lived on the island. At the time, the island had about seven settlements, among which chungliao was the largest. 2. During colonial period, due to low productivity of the island and inconvenience in offisland transports, immigrants led self-sufficient, farming and fishing lives on the island. In this period, population growth on the island was mainly due to natural increase. 3. Since 1950s, a trend of out-migration set off. The major out-migration areas included Taitung Plain and Shingun in the Chengon Prefecture. At the time, some of these emigrants continued their fishing and related activities in the newly settled areas, some, however, looking for better jobs and educational opportunities for their children, moved further on to other parts of Taiwan. 4. Depending on factors influencing population movements, the demographic process on Lu Island can be divided roughly into "the period of in-migration by ethnic Chinese (1799-1861) , " "the period of internal population growth (1861-1961)," and, "the period of outmigration (1961-present)."