  Although direct detection of new particles will be the main focus of the LHC,
indirect New Physics searches are expected to provide useful complementary
information. In particular, precision measurements of rare processes occurring
in flavour physics are of utmost importance in constraining the structure of
the New physics low energy effective Lagrangian. In this paper, few key LHCb
studies, including $B_s-\bar{B}_s$ mixing and rare decays through the quark
level $b\to s$ loop transition, are presented to illustrate New Physics effects
at low energy.
