Traditional distributed intrusion detection systems have many shortcomings, such as heavy interdependence of components and weak reliability of these systems. AAADIDS, which is an acronym for autonomous-agent-based adaptive distributed intrusion detection system, is proposed to solve these problems. The components functions are put up and components collaborations in the network are discussed here. AAADIDS adopts new analysis policies to aim at heavy loads of detection tasks and DCAs to increase system adaptive ability. Compared with the traditional distributed intrusion detection systems, AAADIDS is a more adaptive and efficient system.