Abstract: The present invention relates to the novel use of lignan compounds represented by Formula I. More particularly, the present invention relates to a pharmaceutical composition for treating or preventing a brain disease, comprising a lignan compound represented by Formula I or a Myristica fragrans extract as an active ingredient, as well as the method and use for treating or preventing a brain disease using the lignan compound. The lignan compound represented by Formula I has the effects of antioxidation, brain cell protection and antiinflammation. Accordingly, said lignan compound will be highly useful for treating or preventing a brain disease.