The site-selective excitation and emission spectroscopy and luminescence decay (lifetime) have been investigated in the ${}^5{\mathit{D}}_0\to {}^7{\mathit{F}}_0$ region using a pulsed, tunable, and narrowband dye laser. We observed two crystallographic sites for ${\mathrm{Eu}}^{3+}$ in ${\mathrm{La}}_2({\mathrm{MoO}}_4{)}_3$ and one crystallographic site for ${\mathrm{Eu}}^{3+}$ in ${\mathrm{Gd}}_2({\mathrm{MoO}}_4{)}_3$ . The stark energy levels for ${\mathrm{Eu}}^{3+}$ at different sites were assigned from site-selective emission spectra. The luminescent properties of the as- synthesized samples were also investigated, which showed strong lines at $395\mathrm{nm}$ in excitation spectra and intensive red emission, indicating that they could be used as red components for white LEDs.