中文摘要：

基于1985-2010年沿海城市人口密度数据，利用ArcGIS和空间统计的方法，分析了1985、1990、1995、2000、2005和2010年6个时间节点沿海城市人口密度的时空变化特征，并探讨了沿海城市人口密度变化的驱动因素。结果表明：1985年以来中国沿海城市人口密度整体上呈现不断增长的趋势，2010年沿海城市常住人口总数为2.64亿人，约占全国总人口的19.70%，平均人口密度在640人/km2左右。人口空间分布差异明显，集中表现为区域中心城市人口密度大，南通市以北地区大部分沿海城市的人口密度小于南通市以南的沿海城市。自然因素、经济因素、城市地位与功能、国家政策以及城市发展历史等是沿海城市人口密度差异的主要驱动因素，其中人口迁入已成为影响人口密度时空变化的最重要驱动力。为进一步促进沿海城市人口的合理分布，建议加强引导沿海地区人口有序流动，积极发展中小城镇，注重提高环境的承载力，促进人口、资源与环境的可持续发展。

英文摘要：

Based on population density statistics data of the coastal cities in China during 1985-2010, this paper analyzes the spatial-temporal distribution characteristics and variation trends of population density in coastal cities by using the tool of ArcGIS and spatial statistics method. The driving factors of the changes of population density are also discussed. The results indicated that the population density of coastal cities showed a rapid growth trend since 1985, the permanent residents of coastal cities in 2010 were 264 million, accounting for about 19.70%of the total population of China. The natural population growth was far less than the mechanical growth in the coastal areas. Differences in spatial distribution of population were very notable, the population densities of regional central cities were larger than those of other cities. Population densities of the cities in northern part of coastal China were lower than those in southern part and the transition city between the two parts was Nantong City. Natural environment, regional economic development, city status and function, government policy and urban development history were the most critical factors on differences of coastal city population density in China. The impact of various factors on the coastal urban population density is relatively complex, among those the social and economic factors are becoming the most critical. In order to further promote the rational distribution of coastal urban population, some suggestions are put forward in the paper, such as strengthening guidance on beneficial and orderly population flow, developing medium and small towns actively, paying more attention to improving the bearing capacity of the environment, promoting the sustainable development of population, resources and environment.