The niobate layered oxides intercalated with Tb3+ or EU3+ ions were prepared by the electrostatic self-assembly deposition method. The Tb3+ ions in the interlayer exhibited green luminescence by energy transfer from the host NbO6 layer to the guest Tb3+ ions, which was based on the niobate nanosheet band gap excitation. The Tb3+ emission intensity decreased with decreasing interlayer water molecules, indicating that the presence of interlayer water molecules is inevitable for the Tb3+ emission assigned to the energy transfer. On the other hand, the emission intensity of EU3+ in the interlayer was weaker than that of Tb3+.