Abstract: In this paper,the relative density of 34%,78%of the sand foundation bearing capacity on the basis of centrifugal model test round,the basis of size effect on the relative density of phase with the variation of quantitative discussions to determine the density and stress level sand foundation dependent coefficient and scale effect based on the width limits of specific correspondence.Through this study,to determine the stress level dependence coefficient,based on the scope and size effect of the specific density of sand foundation correspondence.In the capacity tests,according to different density of the foundation,choose a different base size in order to avoid the scale effect.At the same time the basis for the existence of size effect of situation can also be used to compare the test results this exact amendment to eliminate the scale effect.