The theory of complex adaptive system emphasizes agents' adaptability to the environment. As a complex adaptive system,some of the erterprise's behaviors such as the construction process of dynamic capabilities embody the process of adapting to the environment and obtaining new advantages, so CAS theory provides nwe paradigms and frame for studying enterprises' behavior. In this paper,CAS theory and emergence mechanism are applied in discussing the construction mechanism of enterprises' dynamic capabilities from the perspective both of self-organization within the enterprise and of how to interact with the environment.