Abstract: Excavation will cause additional stress and deformations to the surrounding buildings. A series of field monitoring exercise of a deep foundation pit are conducted, including lateral wall deflections, soil settlements and building settlements. Field data indicate that the maximum wall deflections increase as the excavation depth increases, and the maximum wall deflection occurs near the excavation face. The wall deflection is accounted for 91.8% of the final wall displacement when the slab is cast in place. The settlement increases firstly and decreases sharply as the value of x/H_e increases (x, the distance from the wall in the horizontal direction; H_e, excavation depth). The soil settlement is relatively large, while the differential settlement is small when x<16 m, however, the soil settlement is relatively small, while the differential settlement is large when 10 m< x <28 m. The building settlements at the time the slab is cast in place is accounted for 76.6%, 71.5%, 56.8% of the final building settlements with the value of x being 9.6 m, 27.6 m, 45.2 m, respectively. The settlement profile of the five-storey building varies with x and is different from that of soil settlement. However, the settlement profile of the two or three-storey building varies when x is similar to that of soil settlement. The building settlement is relatively large, while the differential settlement is large when y<30 m (y, the distance from the excavation corner in the longitudinal direction), however, the building settlements are relatively small, while the differential settlement is small when y>30 m.