  The D0 collaboration has announced the observation of the like-sign dimuon
charge asymmetry since 2010, which has more than 3\sigma deviation from the
Standard Model prediction. One of the promising explanation is considering the
existence of flavor changing Z' couplings to the b and s quarks which can
contribute to the off-diagonal decay width in the B_s - \bar{B}_s mixing. Model
construction is highly constrained by the recent LHCb data of 1fb^{-1}
integrated luminosity . In this paper, we analyze the experimental constraints
in constructing new physics models to explain the dimuon charge asymmetry from
the CP violation of the B_s system. We present limits on Z' couplings and show
that it is impossible to obtain the 1\sigma range of the dimuon charge
asymmetry without the new contribution in the B_d system. Even with arbitrary
contribution in the B_d system, the new couplings must be in the fine tuned
region.
