Abstract: The coastal zone is a special geographical area with dual properties of land and sea and can realize its evolution through the cross-system and multi-dimensional flow of elements. Grasping the spatial evolution law of the coastal zone is of great significance to promoting the coordinated development of land and sea. The theories related to ‘spatial element flow’ are introduced. The concept of spatial element flow in the coastal zone under the background of land - sea coordination is focused on. The characteristics of the flow are explored. And the results are made to be implemented in the planning and management of the coastal zone. Firstly, the background of land-sea coordination research is outlined, and the theories relative to ‘flow space’, regional element flow and geographic flow research are combed. And then, the conceptual connotation of the spatial element flow in the coastal zone and its spatial pattern distribution are expounded from the aspects of concept definition, element classification and spatial pattern. Finally, the response mechanism and path of coastal zone planning are discussed based on the characteristics of flow coupling. The aim is to provide theoretical support for the coordinated development of land and sea.