Taking Hainan Island as a case and using the panel data of population, economics and social infrastructure from national census and public reports of the 18 cities and counties, this paper examined the spatio-temporal dynamic characteristics and its influencing factors of registered population urbanization in 2000-2018 utilized the methods of spatial autocorrelation and multi-linear regression. The results shows that, firstly, the years 2004 and 2015 are both turning points for the urbanization of Hainan's registered population, which can be divided into three stages: 2000-2003, 2004-20014, and 2015-2018. In nearly 20 years, the urbanization level of the registered population in Hainan Island increases slowly and has achieved remarkable success, each stage shows different fluctuation features due to the changes of local policies and other influencing factors;Spatially, the agglomeration features are dominated by significant discrete distribution, and the distribution pattern and agglomeration types vary greatly; Migration preferred to place with higher payment, economy well-developed, better educational level, more employment opportunities. However, either industry structure or investment was not as effective as hoped, which reflected some problems behind the urbanization growth. For example, the in-migration in Hainan Island was mainly from rural areas, they usually cannot have the same rights as registered population. During the development of the free trade port, increasing the urbanization of registered population is significantly important for improving the urbanized quality. Therefore, it is essential to enhance the management of household registration, accelerate the ability of local urbanization in rural areas, and narrow the gap between urban and rural public services to ensure the residential living standards.
