Split Generation in the SUSY Mass Spectrum and B_s-{bar B}_s Mixing

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.