The crystals of NaLn(WO4)_2(Ln=La,Pr,Nd)are grown from a melt of LiCl-Na_2WO_4 flux by slowcooling method.The chemical analysis data show that the crystals are NaLa(WO_4)_2,NaPr(WO4)_2 andNaNd(WO_4)_2 respectively.The structures of the crystals are ascertained that they belong to scheelite structureof the tetragonal system with a space group of 14_1/a.The lattice parameters of the crystals have beencalculated.It is found that the cell volume of NaLn(WO_4)_2 crystals decrease with a decrease of Ln~(3+)radius.The bond distances and their angles in NaLa(WO_4)_2 and NaNd(WO_4)_2 are given.It is found that inaccordance with the decrease of ionic radii of Ln~(3+)due to increase of atomic number,the bond distances betweenLn-O,Ln-Ln and W-O decrease regularly.The infrared spectra of NaLn(WO_4)_2 are measured.Thetetrahedra characteristic absorptions of WO_4~(2-)are shown.The sensitization of host lattice is observed from theexcitation and fluorescent spectra of NaLa(WO_4)_2 and NaPr(WO_4)_2. The crystals of NaLn (WO4) _2 (Ln = La, Pr, Nd) are grown from a melt of LiCl-Na_2WO_4 flux by slowcooling method.The chemical analysis data show that the crystals are NaLa (WO_4) _2, NaPr _2 andNaNd (WO_4) _2 respectively. The structures of the crystals are ascertained that they belong to scheelite structure of the tetragonal system with a space group of 14_1 / a. The lattice parameters of the crystals have been calculated. It is found that the cell volume of NaLn (WO_4) _2 crystals decrease with a decrease of Ln ~ (3 +) radius.The bond distances and their angles in NaLa (WO_4) _2 and NaNd (WO_4) _2 are given. It is found that inaccordance with the decrease of ionic radii of Ln ~ (3+) due to increase of atomic number, the bond distances between Ln-O, Ln-Ln and WO decrease regularly. The infrared spectra of NaLn (WO_4) _2 are measured. -) are shown. The sensitization of host lattice is observed from theexcitation and fluorescent spectra of NaLa (WO_4) _2 and NaPr (WO_4) _2.