  We show that the like-sign di-muon anomaly reported recently by the D0
Collaboration can be explained in the supersymmetric standard model (SM) if the
squarks and the sleptons in the first two generations have relatively small,
but degenerate mass spectrum, and those in the third generation are larger as
O(1-10)TeV. This split generation model provides large contributions to the
B_s-{\bar B}_s mixing, although most of the FCNC's are suppressed due to the
large masses of the third generation squarks or the GIM mechanism partially
acting on the first and second generations.
