Measurements of the top quark mass and the ttbar production cross
section, obtained by CDF and D0 Collaborations at the Tevatron are presented.
The methodology of analyses and their underlying assumptions are summarized.
The CDF and D0 top mass averages, based on approximately 100 pb^-1 of data
collected by each experiment in Run-I, and obtained from a set of selected
measurements in several channels are M_t = 176.0 +/- 4.0(stat) +/- 5.1(syst)
GeV/c^2 and M_t = 172.1 +/- 5.2(stat) +/- 4.9(syst) GeV/c^2, respectively.
The combined Tevatron top quark mass is M_t = 174.3 +/- 3.2(stat) +/-
4.0(syst) GeV/c^2, where the correlations between CDF and D0 averages were
taken into account.  The CDF measurement of the tt-bar cross section (assuming
M_t = 175 GeV/c^2) is sigma_tt = 7.6 +/- ^1.8 _1.5 pb, and the D0 value
(assuming M_t = 172.1 GeV/c^2) is sigma_tt = 5.9 +/- 1.7 pb.  In anticipation
of the much increased statistics in Run-II, the fact that top quark physics is
one of the best windows to new physics beyond the Standard Model is
emphasized.