The coastlines of China were extracted using remote sensing and GIS techniques based on remote sensing images of Landsat TM, ETM+ and HJ-1A between the year of 1990 and 2013. Then the spatial-temporal changes of the length and utilization intensity of coastlines were analyzed. For the purpose of sustainable use of coastline, two evaluation indices that are utilization intensity and resources’ vulnerability were put forwarded. The results show that: 1) the length coastline of China increased 1045.54 km during the research period. A large number of natural coastlines were changed into artificial coastlines, so the length of artificial coastlines increased by 4398.14 km. The proportion of artificial coastlines in China reached 56.29% in 2013. 2) The intensity of coastlines utilization was increasing in the past two decades. The proportion of developed and utilized area within one kilometer to coastline has reached 80%. The length of heavily used coastline is 3118.05 km, accounting for 16.43% of the total length. The heavily used coastline in Hebei, Tianjin, Shandong, Shanghai, Jiangsu and Zhejiang respectively takes more than 50%, and the unutilized coastline takes less than 30% of the length in each province. While the unutilized coastline in Hainan, Fujian and Guangxi all take more than 60% of the length. 3) The coastlines with low vulnerability mainly distribute in Fujian, Guangdong, Hainan and Shandong. Highly vulnerable coastlines account for more than 15% in northern coastal areas except Shandong Province.