  We present the entanglement properties of the spin-orbital coupling systems
with multiple degrees of freedom. After constructing the maximally entangled
spin-orbital basis of bipartite, we find that the quantum entanglement length
in the noninteracting itinerant Fermion system with spin and orbit is
considerably larger than that in the system with only spin. In the
SU(2)$\otimes$SU(2) spin-orbital interacting system, the entanglement,
expressed in terms of the spin-orbital correlation functions, clearly manifests
the close relationship with the quantum phases in strongly correlated systems;
and the entanglement phase diagram of the finite-size systems is in agreement
with the magnetic and orbital phase diagram of the infinite systems. The
application of the present theory on nucleon systems is suggested.
