  Neutron electric dipole moment (EDM) due to single quark EDM and to the
transition EDM is calculated in the minimal supersymmetric standard model.
Assuming that the Cabibbo-Kobayashi-Maskawa matrix at the grand unification
scale is the only source of CP violation, complex phases are induced in
parameters of soft supersymmetry breaking at low energies. Chargino one-loop
diagram is found to give the dominant contribution of the order of
$10^{-27}\sim 10^{-29}\:e\cdot$cm for quark EDM, assuming the light chargino
mass and the universal scalar mass to be $50$ GeV and $100$ GeV, respectively.
Therefore the neutron EDM in this class of model is difficult to measure
experimentally. Gluino one-loop diagram also contributes due to the flavor
changing gluino coupling. The transition EDM is found to give dominant
contributions for certain parameter regions.
