The depth of the foundation pit area 1 of Runhua Globe Center reached 18 meters, and it was constructed by using cast-in-situ bored piles and inner bracing structure. Vertical settlement and horizontal displacement at the surface around the deep foundation pit were monitored during and after the foundation engineering construction. By the completion of the construction, the subsidence and horizontal displacement reached the stable values of 25mm and 40mm respecively, the supporting effect was coincided with the design requirements. However, monitored values increased suddenly just at the time after the third excavation and before the second support completion and the growth rate were slowly decreased until the second supporting structures were completed. It is advantageous to reduce the deformation of foundation pit and improve the supporting effect by increasing the designed elevation of the second supports.