Coastal zone is a land-sea transitional area with the strongest land-ocean interaction, a complex and dynamic natural earth surface system, and also a spatial unit heavily impacted by both intensive human activities and global climate change. This paper analyzed the ten ecological environmental problems which affect the sustainable development of coastal zone in China, reviewed the international developments and trends of coastal science based on the Land-Ocean Interaction in the Coastal Zone(LOICZ) and the Future Earth Coast(FEC), and also sketched the progresses and gaps in China. Furthermore, the general research ideas, objectives, and contents of coastal science and sustainable development were discussed in relation to the above-mentioned coastal problems. It was emphasized that the research on coastal land-ocean interaction and sustainable development under influences of human activities and global climate changes extends far beyond traditional geography and oceanography. A three-zone conception was put forward for discussion in light of natural and social characteristics in the coastal zones, namely featured core(the strongest land-ocean interaction) zone, adjacent(stronger land-ocean interaction) zone, and peripheral(weak land-ocean interaction) zone. Finally this paper pointed out that coastal science is a comprehensive and across discipline studying the natural attributes and functions, land-ocean interaction, and sustainable development in the coastal zones, and is an irreplaceable featured subject that is greatly helpful for understanding coastal zone regularity and supporting coastal sustainable development.