  We present the results of a phenomenological study of unpolarized nuclear
structure functions for a wide kinematical region of x and Q^2. As a basis of
our phenomenology we develop a model which takes into account a number of
different nuclear effects including nuclear shadowing, Fermi motion and
binding, nuclear pion excess and off-shell correction to bound nucleon
structure functions. Within this approach we perform a statistical analysis of
available data on the ratio of the nuclear structure functions F_2 for
different nuclei in the range from the deuteron to the lead. We express the
off-shell effect and the effective scattering amplitude describing nuclear
shadowing in terms of few parameters which are common to all nuclei and have a
clear physical interpretation. The parameters are then extracted from
statistical analysis of data. As a result, we obtain an excellent overall
agreement between our calculations and data in the entire kinematical region of
x and Q^2. We discuss a number of applications of our model which include the
calculation of the deuteron structure functions, nuclear valence and sea quark
distributions and nuclear structure functions for neutrino charged-current
scattering.
