  We study the entanglement entropy(EE) of disordered one-dimensional spinless
fermions with attractive interactions. With intensive numerical calculation of
the EE using the density matrix renormalization group method, we find clear
signatures of the transition between the localized and delocalized phase. In
the delocalized phase, the fluctuations of the EE becomes minimum and
independent of the system size. Meanwhile the EE's logarithmic scaling behavior
is found to recover to that of a clean system. We present a general scheme of
finite size scaling of the EE at the critical regime of the Anderson
transition, from which we extract the critical parameters of the transition
with good accuracy, including the critical exponent, critical point and a
power-law divergent localization length.
