Abstract: In this work Azo dye {(2,2'-(3,3'-dimethylbiphenyl-4,4'-diyl) bis (1-(2-hydrazinyl-3,5-dinitrophenyl)diazene)} have been prepared and characterized by, spectorphotometric method UV-Vis, FT-IR spectrum and 1H-NMR spectrum. The absorption maxima was observed in the 464 nm, Thermogravimetric(TG) and differential scanning calorimetry (DSC) of this compound was measured, The photostability of azo dye in water occurred under UV irradiation processes. Dyeing process has on the dye prepared it gave good results. we have found that the colors of cotton fabrics after dyeing was orange