  The supersymmetric QCD corrections to top quark pair production by $q\bar q$
annihilation in $p\bar p$ collisions are calculated in the minimal
supersymmetric model. We consider effects of the mixing of the scalar top
quarks on the corrections to the total $t\bar t$ production cross section at
the Fermilab Tevatron. We found that such correction is less sensitive to
squark mass and gluino mass than in no-mixing case, and in both cases the
corrections can exceed 10\% even if we consider the recent CDF limit on squark
and gluino masses.
