Abstract: As a positive defense technology, Network Security Situational Awareness has become the orientation of research in the field of network security. Based on the analysis of the papers from domestic and foreign on technologies for network security situational awareness, a method of network security situational awareness based on the profound research of AIS was designed and built. I}he method uses network intrusion detection based on the theory of immunity as the base of situational awareness, to detect known and unknown intrusions with the help of biological technology. According to correspondence relations of density change of antibody in the artificial immune systems and pathogen invasion intensity, a novel network security situational evaluation model was also established. In the tendency prediction for network security situational,this paper used Urey Markov Model to make quantitative prediction. Experiment results show that this model is also helpful to resemble network security tragedy effectively, therefore, it is a better solution for network security initiatives defense.

Key words: Artificial immunity, Network security, Network security situation