  The observational relation between the density of baryon and dark matter in
the Universe, $\Omega_{\rm DM}/\Omega_B\simeq 5$, is one of the most difficult
problems to solve in modern cosmology. We discuss a scenario that explains this
relation by combining the asymmetric dark matter scenario and the spontaneous
baryogenesis associated with the flat direction in the supersymmetric standard
model. A part of baryon asymmetry is transferred to charge asymmetry $D$ that
dark matter carries, if a symmetry violating interaction that works at high
temperature breaks not only $B-L$ but also $D$ symmetries simultaneously. In
this case, the present number density of baryon and dark matter can be same
order if the symmetric part of dark matter annihilates sufficiently. Moreover,
the baryon number density can be enhanced as compared to that of dark matter if
another $B-L$ violating interaction is still in thermal equilibrium after the
spontaneous genesis of dark matter, which accommodates a TeV scale asymmetric
dark matter model.
