  We introduce the strong CP-violation in the framework of AdS/QCD model and
calculate the electric dipole moments of nucleons as well as the CP-violating
pion-nucleon coupling. Our holographic estimate of the electric dipole moments
gives for the neutron d_n=1.08 X 10^{-16} theta (e cm), which is comparable
with previous estimates. We also predict that the electric dipole moment of the
proton should be precisely the minus of the neutron electric dipole moment,
thus leading to a new sum rule on the electric dipole moments of baryons.
