Most intrusion detection expert system of network adopted single reasoning mechanism.However
rule-based reasoning or case-based reasoning had advantages and disadvantages.The adoption of single reasoning mechanism would lead to inaccurate intrusion detection.The paper proposed mixed reasoning mechanism based on rule-based reasoning and case-based reasoning.On the base of this
the paper designed an intrusion detection expert system of network based on agent
namely AIDES.The experiments indicate that AIDES is effective.