  The direct limit of electric dipole moment (EDM) and direct search for dark
matter by EDM interaction are considered as including the electromagnetic
nuclear form factor, in case that the dark matter candidate is a Dirac
particle. The WIMP electric dipole moment constrained by direct searches must
be lower than 7*10^(-22)e cm for WIMP mass of 100 GeV to satisfy the current
experimental exclusion limits at XENON10 and CDMS II. We also consider the CP
violation of EDM and the WIMP discovery by EDM intereaction in the future.
