Abstract: The author narrates the development and the present situation of the intrusion detection technique,analyses the intrusion detection technique and its characteristics adopted at present,and search the feasibility that ANN(Artificial Neural Network) technology can be applied to anomaly intrusion detection.It designs an Agent-based Distributed Intrusion Detection System.The DIDS system combines host-based intrusion detection and network-based intrusion detection functions.It can be used to protect large area network and have relatively good expansibility.This paper also discusses the implementation of BP neural network in intrusion detection and designs variable learning rate BP regression neural network.

Key words: network security, intrusion detection, neural network