  We investigate entanglement between electronic and nuclear degrees of freedom
for a model nonadiabatic system. We find that entanglement (measured by the von
Neumann entropy of the subsystem for the eigenstates) is large in a statistical
sense when the system shows ``nonadiabatic chaos'' behavior which was found in
our previous work [Phys. Rev. E {\bf 63}, 066221 (2001)]. We also discuss
non-statistical behavior of the eigenstates for the regular cases.
