In the present invention, a method of inhibiting fatty liver disease is disclosed. The method comprises administrating an effective amount of an angelica extract to a subject in need thereof at a dosage of 150 to 600 mg for per kilogram per day of the subject in need, lasting for 4 weeks. The angelica extract is obtained by extracting roots of Chinese angelica through a process of supercritical fluid extraction, water extraction, or organic solvent extraction. A preparation method of the angelica extract is also disclosed in the present invention.
