Abstract: Boussinesq′s elastic solution as well as the Schlecher′s coefficients were frequently used in estimating immediate settlements of buildings in different codes and manuals.Yegorov′s elastic solution has also been used in several domestic codes formulated recently,in which the deformation modules will be unavoidably employed.Because the difficulties in deriving the deformation modules E 0 from either laboratory or in situ tests,limited amount of data is reported in the literature .The nonliner behavior of equivalent deformation modules E 0eq derived from plate loading tests performed on three main types of soils in Beijing area was studied in this paper using the p-s curves and their characteristic values. Mathematical expressions for the equivalent deformation modules varying with pressure p were established.