[Purpose/significance] By introducing the principles and methods of ecology into the study of knowledge organization system, the functions and actions of knowledge organization system can be brought into full play. [Method/process] Based on the research results of ecology, the principles and methods of ecology are introduced into the construction and application of the knowledge organization system. The biological individual corresponds to the concept individual, the species population and the concept correspond, the biological community and the vocabulary correspond, the biological environment corresponds to the literature environment and on the basis of the complete and consistent correspondence of the structure and function, the working principle and method of the knowledge organization system are studied. [Result/conclusion] The framework of the knowledge organization ecosystem is refined and perfected, and the main contents of each level are analyzed and summarized in the four aspects, including the concept instance, the concept population, the concept community (vocabulary) and the ecosystem.