We summarize a discovery potential for supersymmetric particles
at the p anti-p collider of Tevatron with center-of-mass energy s**(1/2) = 2 TeV
and integrated luminosity int L dt = 15-30 fb-1.  Any direct search is
kinematically limited to below 450 GeV/c2.  We, however, have a unique
opportunity to test various supersymmetric scenarios by a measurement of the
branching ratio for the rare decay mode B_s --> mu+ mu-.  Using the
background estimate in the CDF analysis of B_s --> mu+ mu- in Run I, we
investigate the prospects for studying this mode in Run II.  CDF would be
sensitive to this decay for a branching ratio > 1.2 x 10-8 with 15 fb-1
(or, if a similar analysis holds for D0, > 6.5 x 10-9 for the combined
data).  For tan beta > 30, the B_s --> mu+ mu- search can probe the SUSY
parameter space that cannot be probed by direct production of SUSY particles
at Run II.  An observation of B_s --> mu+ mu- with a large branching ratio
> 7(14) x 10-8 (feasible with only 2 fb-1) would be sufficient to exclude
the mSUGRA model for tan beta \leq 50(55) including other experimental
constraints.  For some models, the branching ratio can be large enough to be
detected even for small tan beta and large m_1/2.