In the process of continuous construction and development of urban underground space, more and more foundation pits excavations adjacent subway structures are bringing through. By collecting examples in Guangzhou and in urban, changes of the displacement field after excavation were analyzed and influences of the adjacent constructions of foundation pits on the existing subway structures were summed up. Moreover, Nongmao park project in Guangzhou was selected for numerical simulation using 3D continuous FEM(the finite element method). By comparing and analyzing the results calculated with the measured data, some conclusions which can play reference roles to similar projects in future have been drawn.