Abstract: Deformation prediction of deep excavations is difficult, and pre-warning value is not accurate and reliable because there are many factors to affect their deformation and different controlling factors in different places. It is essential to predict and analyze deformation of deep excavations according to special area and supporting structure. Statistical analysis is conducted to analyze the mass data of monitoring in Hangzhou City to gain the relationship between deformation of supporting structures and surface settlement and bottom upheaval as well as the deformation characteristics and values. Then, the degree of excavations is classified according to its importance and the degree of building importance. Finally, the controlling value of excavation deformation is put forward as the pre-warning value so as to ensure the construction safety of excavation. The conclusion is adaptable to predict the deformation of excavations in Hangzhou.