Abstract:An in-situ monitor was installed on large-scale preloading field,where the field monitoring was preformed and lasted for three years. With the help of the date analysis of field monitoring,the paper presents the correlations among subsoil deformation, preloading construction,subsoil properties,permeability coefficient,and time period. It is found that deformation properties of soft subsoil under large-scale preloading are different from these under common loading,and the deformation and consolidation laws of soft subsoil with different border conditions during the period of preloading are obtained. The achieved results can provide a basis for the analysis and calculation of consolidation and settlement for soft subsoil.