  The study of nuclear effects for J/{\psi} production in proton-nucleus
collisions is crucial for a correct interpretation of the J/{\psi} suppression
patterns experimentally observed in heavy-ion collisions. By means of three
representative sets of nuclear parton distribution, the energy loss effect in
the initial state and the nuclear absorption effect in the final state are
taken into account in the uniform framework of the Glauber model. A leading
order phenomenological analysis is performed on J/{\psi} production
cross-section ratios RW/Be(xF) for the E866 experimental data. The J/{\psi}
suppression is investigated quantitatively due to the different nuclear
effects. It is shown that the energy loss effect with resulting in the
suppression on RW/Be(xF) is more important than the nuclear effects on parton
distributions in high xF region. The E866 data in the small xF keep out the
nuclear gluon distribution with a large anti-shadowing effect. However, the new
HERA-B measurement is not in support of the anti-shadowing effect in the
nuclear gluon distribution. It is found that the J/{\psi}-nucleon inelastic
cross section {\sigma} J/{\psi} abs depends on the kinematical variable xF, and
increases as xF in the region xF > 0.2. 1 Introduction
