  Sytematic uncertainties to the single top production cross section
measurement at the ATLAS experiment has been studied. Different sources of
systematic uncertainties such as detector luminosity, jet energy calibration,
SM background normalization, PDF parameterization and others have been
considered. Large scale Monte-Carlo events simulation has been performed to
estimate the contribution of each source in the overall uncertainty. The study
was done for cut based analysis as well as for multivariate analysis of the
single top measurements in ATLAS. The total systematic uncertainties of the
single top cross-section measurements in its three production channels have
been estimated at 1 $\mathrm{fb}^{-1}$ and 10 $\mathrm{fb}^{-1}$ integrated
luminosity of the LHC.
