Expasion of computer network and rapid growth of Internet have made computer security very important. As one of the ways to deal with security risk, much research has been made on Intrusion Detection System(IDS). The paper, also, addresses the issue of intrusion detection, but especially with Neuro-Fuzzy model. By applying the fuzzy logic which is known to deal with uncertainty to Anomaly Intrusion, it not only overcomes the difficulty of Misuse Intrusion, but also ultimately aims to detect the intrusions yet to be known.