As the traditional methods, the result of vulnerability scanning can’t directly reflect complex attack routes existing in network, so the concept of attack graph comes. After analyzing host computer, devices link relation and the characteristic of attack, the model of network security status was built. Attack graphs are one of the important tools for analyzing security. A lot of research has been done on issues such as scalable and time efficient ways of generation of attack graphs. The intent of this paper is to study different ways to generate an attack graph and to provide future scope for research on these attack graphs.