Abstract: The soil structural quantitative parameter (strain comprehensive structure potential) was introduced into the analysis of soil strength and deformation characteristics. Under the same confining pressure, the stress-strain curves of sand with different water content were in a stripe region. Using the similar method of setting up the Duncan-Chang model, structural constitutive model of sand was constructed and the parameters of the model were obtained by testing. Results of calculation and test show that the constructed structural constitutive model could better reflect the relationship of stress and strain of sand under different water contents.