  The recent measurements of the top anti-top quark pair production
cross-section in proton antiproton collisions at sqrt{s}=1.96 TeV in lepton +
jets and dilepton (including tau lepton) channels are presented. These
measurements are based on 1 fb^{-1} of data collected with the DO experiment at
the Fermilab Tevatron collider. The measured values are compatible with the
standard model prediction and have the uncertainty close to the uncertainty of
the theoretical prediction ~10%.
