Abstract: Inspired by the self-adaptation,diversity,memory ability in artificial algorithm,and combining the robustness and distribution in multi-agent system's architecture,an immune multi-agent active defense model for network intrusion is established;the concept of immune agent is introduced;and its logical structure and running mechanism are established.This model implements the multi-layer and distributed active defense mechanism for network intrusion.Experiment results show that this model is a good solution to the network security defense.