Dyeing properties of the colorants extracted from acorn on wool fabric were investigated. Effects of dyeing temperature, dyeing time, repeating, and pH on dye uptake and colorfastness were explored. Acorn colorants showed very good affinity to wool fiber and produced bright to dark brown color ranged 4.81-8.97YR, 4.46-7.47/1.79-3.35. ,Higher temperature increased dye adsorption, so did longer time and more repeating. Washfastness was fairly good. The Dyed wool fabric had deeper color after irradiation to light. pH had an effect on the development of color, also. Dye uptake and washfastness were higher in acidic and alkaline pH than in neutral pH solution.