Data streams are continuous flow of data include network packets, surveillance, financial market and day-to-day business. Their volume and speed is a great challenge for data mining community to mine them A large number of researches have been proposed on intrusion detection system, which leads to the implementation of agent based Intelligent IDS (IIDS), Non – Intelligent IDS (NIDS), signature based IDS etc. While building such IDS models, learning algorithms from flow of network traffic plays crucial role in accuracy of IDS systems.