Abstract: The contradiction between industrial development and ecological environment along the Yangtze river is prominent. The demarcation of the ecological red line along the Yangtze river is of great significance to the ecological protection and the orderly development of the Yangtze river coastline. This paper combs the concept and connotation of the ecological red line, and summarizes the research status and theoretical basis of the ecological red line. This paper establishes the evaluation index system of ecological red line of the Yangtze River coastline from three aspects: ecological sensitivity, importance of ecological function and prohibition of development zones. Finally, the technical method and process of delimiting the ecological red line along the Yangtze River coastline are established. The ecological red line demarcation method is applied to the Yangtze river coastline. The research results show that the length of the first-grade protection zone of the ecological red line on the Yangtze River coastline is 597.11 km, accounting for 7.55% of the length of the Yangtze River coastline. It includes Jingzhou, Xianning, Anqing and other parts of the coastline. The ecological red line first-level protection zone implements the most stringent control measures and prohibits any development and construction activities. The length of the second-level protection zone of the ecological red line on the Yangtze River coastline is 1171.29 km, accounting for 14.81% of the total length of the Yangtze River coastline. It includes some shore sections such as Yueyang, Chizhou and Suzhou. The intensity of space development activities should be strictly controlled in the secondary ecological red line protection zone. The secondary protection zone should ensure that the ecological red line function is not reduced, the red line area is not reduced, and the resource utilization is not exceeded. This study has important theoretical and practical value and significance for constructing the ecological security pattern of the Yangtze River coastline.