  Gribov theory is applied to investigate the shadowing effects in the
structure functions of nuclei. In this approach these effects are related to
the process of diffractive dissociation of a virtual photon. A model for this
diffractive process, which describes well the HERA data, is used to calculate
the shadowing in nuclear structure functions. A reasonable description of the
x, Q^2 and A-dependence of nuclear shadowing is achieved.
