  In this article, we study the doubly heavy baryon states $\Xi_{cc}$,
$\Omega_{cc}$, $\Xi_{bb}$ and $\Omega_{bb}$ in the nuclear matter using the QCD
sum rules, and derive three coupled QCD sum rules for the masses, vector
self-energies and pole residues. The predictions for the mass-shifts in the
nuclear matter $\Delta M_{\Xi_{cc}}=-1.11\,\rm{GeV}$, $\Delta
M_{\Omega_{cc}}=-0.33\,\rm{GeV}$, $\Delta M_{\Xi_{bb}}=-3.37\,\rm{GeV}$ and
$\Delta M_{\Omega_{bb}}=-1.05\,\rm{GeV}$ can be confronted with the
experimental data in the future.
