On the Phase of B⁰--bar {B⁰} Mixing Matrix Elements in the SUSY Standard Model

It is shown that the complex phase of $B^0$--$\bar {B^0}$ mixing matrix element is same as that of the standard model one up to the minor correction of the order of $(m_c/m_t)^2$ or less in the SUSY standard model. This conclusion is valid as far as the Yukawa coupling constants are perturbative and realistic, and can be available for other realistic models where generation mixing and CP violation are solely due to Yukawa interaction among quarks and Higgs doublets.