Good quality of semi organic single crystals of a urea cupric sulphate ( UCS)was grow from solution by s low evaporation technique at room temperature. Goodoptical quality s ingle crystals with dimensions 15 × 11 × 3 mm 3 were obtained.The grown crystal had been confirmed by single X- Ray Diffraction Method. UV -Vis absorption,s tudies reveals that the grown crystal was optically transparentthrough the visible range. The vibrational frequencies of various functionalgroups in the crystals had been derived from Fourier transform infrared spectrum.Dielectric studies have been made. Dielectric studies give information about thecharge transport mechanism of a material. The optical absorption studies indicatethat for the sample, optical transparency window w is quite wide, making it tsuitable for NLO applications