Tectonofractography is a new branch of tectonophysics, which provides useful information regarding fracture history and mechanism of rock fracture, based on the fractographical features. This paper aims at introducing tectonofractography and its application to site investigation for engineers.Historical review on the development of tectonofractography is first presented in this paper, followed by introducing basic morphologies of rock fracture, to establish basic understanding of this discipline to the readers. The application of tectonofractography to site investigation is then presented through three practical cases. With more understanding about tectonofractography, the engineers can thus gain more information from site investigation.