The wide spread use of computer networks in today's society, especially the sudden surge in importance of the World Wide Web, has made computer network security an international priority. Since it is not technically feasible to build a system with no vulnerabilities, intrusion detection (ID) has become an important area for researches. An intrusion that deviates only slightly from a pattern derived from the audit data may not be detected or a small change in normal behavior may cause a wrong data. Intrusion detection systems (IDS) offer techniques for modeling and recognizing normal and abusive system behavior. GAs can be successfully used to tune the membership functions used by the IDS. In this paper a survey were performed approaches based on IDS, and on implementing of GAs (GAs) on IDS.