Immune-SoftMan (ISM), a new concept, is an immune intelligent entity. ISM lives and acts in the computer network environment. It has great capabilities to deal with some things in certain circumstances without manual intervention and supervision. Comparing with Agent and Robot, ISM not only has more all-around humanized intelligence, humanized behavior and function, but also has the ability of environment identifying, network migration, self-determination and free will. In this paper, the concept, characteristics and individual overall model of ISM are presented. This system model can monitor the distributed dynamic network environment in real time, and alarm and diagnose faults in advance. On the basis of these, a novel ISM architecture is constructed and discussed. The presented architecture can achieve a self-organizing system that is more robust and flexible in dynamic network environment, and can be self-updated locally. ISM’s theory and technology fruits also provide a good foundation and reference for studying the present network security system.