Abstract: Soilmodel parameters are critical in assuring reliability of numerical results of commonly used finite elementmethod for simulating deformation of supporting structure for deep foundation p it. The Duncan - Chang E- model, a nonlinear elastic modelwidely used in the geotechnical engineering, is chosen in this paper. A retaining structure with double - row p iles is used as an examp le for the sensibility analyses. The results show that the main parameters influencing the deformation of supporting structure are k、G、Rf and . The increase of G、Rf or n can result in an increase in the disp lacement and the increase of k can result in the decrease of the disp lacement. On the whole, the sensibility of the Duncan - ChangModel Parameters to the disp lacement is greater than the sensibility to the moment in the structure.