Abstract: Marine ecological compensation is regarded as one of the hot issues in the marine studies.The existing problems of connotation delimitation and system design in the process of implementation in marine ecological compensation were analyzed in detail in the present work.Based on the peculiarity and complexity of the marine ecological compensation, the concepts of its four basic components (subject, object, mediator and annulus) were delimited, and an in-depth discussion were made on the complicated relationships between different elements in the specific activities, with the notion of marine ecological compensation defined.Combined with the practice of the marine management, the differences among marine ecological protection compensation fees, marine ecological loss compensation fees, marine ecological damage compensation fees and sea area use fees concerning the marine ecological compensation were researched, and related policy suggestions on building up the marine ecological compensation system were offered as well.