Oceans and coastal cities are essential parts of land-ocean ecosystem.The development of coastal cities has strong impact on the ocean and land-ocean ecosystem.Conversely，the city is also significantly affected by the ocean.Most previous urban planning studies pay more attention to the land ecosystem and less focus on the interaction between urban area and ocean.Firstly，this research takes Tianjin Binhai New Area as a case study，and it aims to reveal the overall coordination between the ecological development strategies and ocean ecosystem protection strategies based on the ecologically Synergetic Development of Jing-Jin-Ji.Secondly，the research concludes the patterns and results of the interrelationship between coastal city and marine ecosystem from the impact of coastal city and ocean （climate，geology，ocean hazard，pollutions，biodiversity，coastline change and sea reclamation，etc.）.The research claims the planning strategies and methods of urban sustainable development and land-ocean ecosystem environment protection in Tianjin Binhai New Area.Thirdly，the research analyzes how to reduce the impact of sea reclamation to the ocean ecology.The ecological sea reclamation planning strategy is proposed from urban function area：including density，traffic，coastline form and eco-system to reduce negative effects of reclamation to ocean ecology.Finally，taking Sino-Singapore Tianjin Eco-city as an example，the paper tries to provide suggestions to the space planning for slowing transportation.