  The paper is devoted to the calculation of additional two-loop O(\alpha_s^2)
MSSM corrections to the relation between the pole mass of the t-quark and its
running mass in the DR scheme. The value of the second order contribution from
large mass expansion is studied. As a by-product we calcutated two-loop
anomalous dimension of the running quark DR-mass in the supersymmetric QCD.
