Sm2(WO4)3 crystals have been synthesized through liquid-phase reaction. The structure, morphology and optical properties of the products have been investigated by Fourier transform infrared spectroscopy (FTIR), X-ray diffractometer, SEM, and spectrofluorometer, respectively. The compound crystallized in the monoclinic hexagonal system, space group C2/c. Heat treat promoted the crystallization and regulated the micro-structure of Sm2(WO4)3. In the Sm2(WO4)3 host, the WO42- group could transfer the energy of near-UV light to Sm3+ ions, emitting blue, green and red light at 429 nm (6P5/2→6H5/2), 453 nm (4G9/2→6H5/2), 495, 507 nm (4G7/2→6H5/2), 563 nm (4G5/2→6H5/2), 601 nm ( 4G5/2→6H7/2) and 649 nm ( 4G5/2→6H9/2), respectively. The ratio of blue, green and red light was appropriate to achieve white light. The Sm2(WO4)3 powders have potential to act as UV absorber for solar cell and may be helpful to the development of white light LED.