Abstract: To cope with the security and collective defense mechanism in cyber, software maturity theory is employed and the maturity model of cyber ecosystem is presented. First, based on characteristics of cyber ecosystem and its relationships between decisionmakinTo cope with the security and collective defense mechanism in cyber, software maturity theory is employed and the maturity model of cyber ecosystem is presented. First, based on characteristics of cyber ecosystem and its relationships between decisionmaking, information sharing and elements cooperation, the threedimensional and fiveclass maturity concept model is proposed for cyber ecosystem, as well as key process areas corresponding to the maturity levels. Secondly, the operation system is provided as the demonstration, hierarchical models are brought out for the maturity of cyber ecosystem, and the cyber structure and the corresponding elements function relationships at different levels are systematically explicated. Furthermore, maturity capability models of information decision, elements cooperation and information sharing are proposed, and then simulations are given.g, information sharing and elements cooperation, the threedimensional and fiveclass maturity concept model is proposed for cyber ecosystem, as well as key process areas corresponding to the maturity levels. Secondly, the operation system is provided as the demonstration, hierarchical models are brought out for the maturity of cyber ecosystem, and the cyber structure and the corresponding elements function relationships at different levels are systematically explicated. Furthermore, maturity capability models of information decision, elements cooperation and information sharing are proposed, and then simulations are given.