With the development of the intrusion technology and the uncertainty, complexity and diversity character of the network attack, the next direction will be characterized as large scale, collaboration and multilayered. As a result, modeling of network attack has been the focus of attention. In the current study, firstly, the research background of modeling of network attack and the concept of attack graph are presented. Then the represented network attack graph generating method and its algorithmic complexity are discussed. Finally, the application of network attack graph is given. In conclusion, some major problems and research trends in this area are addressed.