  In the present review we show that renormalizations in a softly broken SUSY
gauge theory are not independent but directly follow from those of an unbroken
or rigid theory. This is a consequence of a treatment of a softly broken theory
as a rigid one in external spurion superfield. This enables one to get the
singular part of effective action in a broken theory from a rigid one by a
simple modification of the couplings. Substituting the modified couplings into
renormalization constants, RG equations, solutions to these equations,
approximate solutions, fixed points, etc., one can get corresponding relations
for the soft terms by a simple Taylor expansion over the Grassmannian
variables. Some examples including the MSSM in low and high $\tan\beta$ regime,
SUSY GUTs and the N=2 Seiberg-Witten model are considered.
