  Nuclear shadowing in the structure function $F_3$ is investigated as a
possible test of shadowing models. The $F_3$ shadowing is studied in two
different theoretical models: a parton-recombination model with $Q^2$ rescaling
and an aligned-jet model. We find that predictions in these models differ
completely in the small $x$ region. It suggests that the $F_3$ shadowing could
be used for discriminating among different models, which produce similar
shadowing behavior in the structure function $F_2$.
