Abstract: As a significant spatial carrier for marine economy developments on coastal areas, the coastline possesses extremely important ecological functions and resource values. Based on the comprehensive analyses of coastline implications and definitions, this paper establishes a sea-land coordinated coastline classification system with respect to the requirements of corresponding managements and practical applications. In addition, by taking into account various coastline delimitation principles, and considering diverse factors (namely, attribute characteristics, administrative specifications and so on) of coastline segments, this paper proposes a series of efficient delimitation methods for different types of coastlines, for example, mark line-based algorithm for natural coastlines, mean water spring-based method as well as comprehensive assessment-based approach, comprehensive assessment-based technique for artificial coastlines, feature sorting-based algorithm for estuarine coastlines, index quantification scoring-based way for restored ecological coastlines and so forth, which are beneficial to the national coastlines in terms of protections, utilizations and managements.