Abstract: Ultrasonic and conventional heating methods were performed to select the best solvent for Osage orange extraction. Distilled water and other co-solvents, such as water-acetone and water- ethanol mixtures were tested at concentrations of 10% v/v. Two grams of Osage orange powder was suspended in 20 cm3 of solvent in a thermostatic and ultrasonic bath. Extraction process was followed by the dyeing of woolen fabric to evaluate data. Ultrasonic assisted extraction at 60°C for 30 min possessed much higher dye absorbance and color strength at lower temperature and time rather than using the conventional heating method. 15% v/v water-acetone co-solvent released 32% of the total dye absorbency and 21% of color strength on the dyed woolen samples, this was followed by water-ethanol co-solvent then water which released 27 and 21% of dye absorbency and 19 and 16% of color strength, respectively. These data are relative to 10, 6 and 4% of dye absorbency and 18, 15 and 11% of color strength with the same co-ordinate solvents in case of using the conventional heating method. Absorption of dye is dependent on solvent polarity. In non-hydrogen-bond donating solvents, solvation of dye molecules probably occurs via dipole-dipole interactions, whereas in hydrogen-bond donating solvents the phenomenon is more hydrogen bonding in nature. Given that both ultrasonic and water acetone co-solvent in extracting Osage orange natural dye, are environmentally and new ecological acceptable for dyeing protein fabrics.