Delineating the red lines of island ecological protection are an important method to maintain island ecological security and coordinate the contradiction between island development and protection. At present, the red lines of island ecological protection have not been unified in terms of concept connotation, delineation content and method it be confused with the concept of marine ecological red lines. Different types and forms of island red line delineation and principle requirements distinguished, for example, single island, archipelago, and non-resident islands and so on. Concept of the island ecological protection red line the difference and relation between the island ecological protection red. Combining the attributes of ecological, and management, this paper expounds the principles of defining the red lines of island ecological protection based on the viewpoint of development and thinking. The main red lines types of island ecological protection include key ecological function areas, the sensitive/fragile areas and the no-development zones of islands the red lines delineation of the island ecological protection some indicators, putting forward the technical route of delineation of the red lines of island ecological protection. At the same time, some problems facing the division of the red lines of island ecological protection. Finally, the study of demarcating the red lines of island ecological protection in the future are prospected.