Abstract:Bays have the inherent advantages in location, environment, and resources because of the unique natural conditions. Bays have been the hub of sea and land transport, industrial base, important city center, and the cradle of marine organism. They have a strategical position in the national economic and social development, thus it is of great significance to keep sustainable development in bays. In last several decades, intense human activities have resulted in the decrease of area and natural shoreline, sediment accumulation, ecological environment deterioration, and ecosystem imbalance in bays, which have seriously threatened the sustainable development of economy and society in coastal areas. Therefore, it is urgent to carry out the integrated marine and land development planning, and the comprehensive ecological environment management and renovation planning in Chinese bays. The input of non-point pollution from watershed should be controlled, and the ecosystem-based management should be promoted in order to maintain ecosystem health and sustainable development in bays.