Na2Ni(SO4)2·4H2O crystal (NNSH) size up to 12mm×10mm×8mm have been grown by heating the solution gradually. The structure of crystal was determined by X-ray diffraction method. The transmission spectra with strong absortpion band at visible and infrared region were measured by using UV-VIS ultraviolet spectrophotometer. Absorption cross-sections of crystal at 344nm and 640nm were evaluated as 4.380×10-18cm2 and 3.63×10-18cm-2,respectively. NNSH was stable at high temperature, for the dehydration temperature of the crystal was determined to be 132.6 °C by thermogravimetric measurement. It was shown that NNSH had strong absorption at visible or infrared region and high thermal stability that may render it to be a filter material as to obtain more pure ultra-violet spectrograph and be accessible in high temperature environment.