Research conclusions: From the statistic analysis of the measured data of the foundation in soft soil area，it sis concluded: ( 1) The maximum deep horizontal displacement value of Grade A foundation pit is concentrated in the 60 －100 mm deep areas and it decreases with the increase of the excavation depth． ( 2) On the premise of no change of the support structure，the deformation volume of the support pile increases obviously，but the deformation law does not change． ( 3) The maximum horizontal displacement of the support pile is basically in nonlinear decrease state with the increase of the elastic modulus．