  Single top quark production through weak interactions is an important source
of charged Higgs in the Minimal Super Symmetric Standard Model. In the
s-channel single top production ,charged Higgs having largest cross-section may
appear as a propagator in the form of heavy resonance state decaying to a pair
of top and bottom quark. In this paper the channel under consideration is $pp
\rightarrow H^{\pm}\rightarrow tb \rightarrow b\bar{b}W^{\pm} \rightarrow
b\bar{b}\tau^{\pm} \nu_{\tau}$, where top quark exclusively decays into a pair
of b quark and W boson while W boson subsequently decays to $\tau$ jet and
neutrino. So the final state is characterized by the presence of two b jets,
hadronic $\tau$ decay and missing transverse energy.It has been demonstrated
that the charged Higgs signal observability is possible within the available
MSSM parameter space (tan$\beta$, $m_{H^{\pm}})$ respecting all experimental
and theoretical constraints due to presence of QCD multijet and electroweak
background events at LHC. In order to show the observability potential of
charged Higgs, the charged Higgs signal are well observed or excluded in a wide
range of phase space particular ($\beta > 35$ at 500 $fb^{-1}$ , $\beta > 25$
at 1000 $fb^{-1}$ , $\beta > 15$ at 3000 $fb^{-1}$ ) at $\sqrt{s}=$14 TeV.
