Let X be a simple, finite C.W.
complex. The group ℰ#(X) is known to be nilpotent. In this paper, we give a proof
of the naturality of localization on this group, ℰ#(X)(P)= ℰ#(X(P)). The result is
then applied to study the group structures of ℰ#(X) of rational Hopf spaces and
some Lie groups.