We show that the recent measurements of BsββBΛsβ mass difference,
Ξmsβ, by D{\O} and CDF collaborations give very strong constraints on
MSSM scenario with large flavor mixing in the LL and/or RR sector of down-type
squark mass squared matrix. In particular, the region with large mixing angle
and large mass difference between scalar strange and scalar bottom is ruled out
by giving too large Ξmsβ. The allowed region is sensitive to the CP
violating phases Ξ΄L(R)β. The Ξmsβ constraint is most stringent
on the scenario with both LL and RR mixing. We also predict the time-dependent
CP asymmetry in BsββΟΟ decay and semileptonic asymmetry in BsβββX decay.Comment: 15 pages, 9 figure