  Motivated by the recent measurement of the like-sign dimuon charge asymmetry,
we investigate anomalous CP violation in the B_s- bar{B}_s mixing within the
supersymmetry. We show that when gluino diagrams dominate supersymmetry
contributions, it is very difficult to realize a large B_s- bar{B}_s mixing
phase under the constraint from electric dipole moments barring cancellations.
This constraint can be ameliorated by supposing superparticles decoupled. In
this limit, we find that it is possible to achieve the large CP asymmetry, and
the branching ratio of B_s -> mu^+ mu^- tends to become sizable.
