According to rapid development and popularity of Internet and online procedures, the potential of network attacks has increased substantially in recent years. Therefore, network security needs to be concerned to provide secure information channels. Intrusion Detection System (IDS) becomes an essential component of computer security. This work is devoted to focus on how to construct a fast accurate NIDS. The book propose two different hybrid NIDS, the proposed hybrid NIDS models involves data pre-processing, data reduction and intrusion classificationtion. Experiments and Analysis of the proposed hybrid NIDSs with other previous NIDSs demonstrated that; the two proposed hybrid NIDSs enhance the intrusion detection rate and decreasing the testing speed.