Background: The English common name of Aqularia sinensis (Lour.) Gilg. IV. (Thymelaeaceae) is Incense Tree, which is known as Oud in Persian. Aquilaria species produce a resin-deposited part of the trunk. The species was once widely planted in Hong Kong as the raw material of incense exported to China, Southeast Asia and places as far away as Arabia. Objective: Investigation of the chemical constituents of the injured or uninjured wood of the plant can offers valuable information in order to know the bioorganic process of resin formation. Methods: Methanolic extracts of the uninjured wood of plant was used in order to isolation of sterols components. Separation and purification of the compounds was carried on silica gel column chromatography and gel permeation chromatography (GPC). Structural elucidation of the constituents was based on the data obtained from H-NMR, 13C-NMR, HMBC, HMQC, DEPT and H-H COSY. Results: Four sterols, stigmast-4-ene-3-one, stigmast-4-ene-3,6-dione, β-daucosterol and β-sitosterol were identified based on spectral data which have never been reported from this plant until now. Conclusion: Methanol extract of Aqularia sinensis consists of sterols, of which stigmast-4-ene-3-one, stigmast-4-ene-3, 6-dione, β-daucosterol and β-sitosterol (with Stigmastan skeleton) are the main compounds and is reported for the first time.