Under various calcination temperatures and with different dosage of PEG-1000, a series of ZnWO4 phosphors were synthesized by hydrothermal process. The samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Scanning electron microscope and Fluorescence spectrophotometer. The results show that as-synthesized blue-emitting phosphors ZnWO4 are pure wolframite structure. The particles of hydrothermal product are spheres in shape, and after calcination at 700 ℃, the morphology is changed from spheres to short rods. Under the condition of adding 0.5 g PEG-1000 and calcination at 700 ℃, the obtained particles are still short rods in shape, but the size is reduced significantly. The emission spectrum of ZnWO4 is composed of a broad band with the main peak at 465 nm. The crystallinity and luminescent property of the ZnWO4 powder synthesized by hydrothermal process can be improved by calcination, and the optimal calcination temperature is 700 ℃. Adding surfactant PEG-1000 can also increase the luminescent intensity of the phosphors, and the optimal dosage is 0.8 g.