By extending the quantifier-free predicate logic (without equality, constant and function symbols) with a bundled modality \(\exists x\Box \) , which packs the quantifier \(\exists x\) and the modality \(\Box \) together, we obtain a fragment of first-order modal logic, namely, \(\exists \Box \) -bundled fragment. In this paper, we prove that the Craig interpolation theorem holds for systems of the \(\exists \Box \) -bundled fragment based on K/D/T/4/S4, while it fails for the system based on S5.