  The enhancement of $J^{\pi}(T)$=3$^{+}$(0) state with isospin $T=0$ excited
by the tensor force in the free $^{6}$Li nucleus has been observed, for the
first time, relative to a shrinkable excitation in the $^{6}$Li cluster
component inside its host nucleus. Comparatively, the excitation of
$J^{\pi}(T)$=0$^{+}$(1) state with isospin $T=1$ for these two $^{6}$Li
formations take on an approximately equal excitation strength. The mechanism of
such tensor force effect was proposed due to the intensive nuclear medium role
on isospin $T$=0 state.
