A series of green-emitting phosphors NaLa1-x(MoO4)2:Tb3+x (x=0.02, 0.1, 0.15) were prepared by a microwave-assisted sol-gel method. X-ray diffraction and fluorescence spectrophotometer were used to analyze the phase structure and luminescent properties of as-synthesized phosphors, respectively. The results show that NaLa(MoO4)2:Tb3+ phosphors possess a tetragonal crystal structure similar to that of NaLa(MoO4)2. The excitation spectrum of NaLa(MoO4)2:Tb3+ is a broad band between 250 nm and 350 nm, and the main peak is at 300 nm. The emission spectrum is composed of a series of sharp lines. The main emission peak is at 544 nm, which is ascribed to the transition of 5D4–7F5. The luminescent intensity of NaLa(MoO4)2:Tb3+ increases with the increase of Tb3+ content, and reaches the maximum when the content of Tb3+ is 10 mol%, and then decreases with the further increase of Tb3+ content. The concentration quenching is caused by the interaction of electric dipole-electric dipole of Tb3+ according to the Dexter theory. Moreover, the luminescent intensity of NaLa(MoO4)2:Tb3+ can be greatly enhanced with incorporation of SO42-.