  Top quark pair production cross section has been measured at the Tevatron by
CDF and $D\O$ collaborations using different channels and methods, in order to
test standard model predictions, and to search for new physics hints affecting
the $t\bar t$ production mechanism or decay. Measurements are carried out with
an integrated luminosity of 1.0 to 2.0 fb$^{-1}$, and are found to be
consistent with standard model expectations.
