Abstract: On the basis of comparison and summarization of theoretical studies on soil anisotropy under the principal stress rotation, a new method for studying the yield suface of a constitutive model under different load directions is proposed. Using this new method, the satisfactory yield function under different load directions can be derived, and taking the Sekiguchi and Ohta model as an example, the yield surfaces under different load directions are plotted in <>p – <> q space. It is valuable to the theoretical researches on anisotropic yield surfaces.