In the paper, the ecosystem of the digital education resources sharing is researched. First, the conceptions of the digital education resources and its sharing are defined, and the theory of the ecosystem is introduced. And then, the constituent elements and the relations of the digital education resources sharing ecosystem are listed. Finally, the natures of it are analyzed to prove the thesis that the digital education resources sharing ecosystem is a internet ecosystem and also a Complex adaptive systems (CAS). The paper provides a new research perspective on the digital educational resources sharing and the researches based it would provide the systematic approach to solve the problems in the digital educational resources sharing.