Abstract: Eight compounds were isolated from the bark of Cercidiphyllum japonicum Sieb. et Zucc. Their structures were identified with spectral and chemical methods as 5, 7-dihydroxy-3, 8, 4′-trimethoxyflavone (Ⅰ), 3,5,7-trihydroxy-8,4′-dimethoxyflavone (Ⅱ), 5,7,4′-trihydroxy -3,8-dimethoxyflavone (Ⅲ), 3,5, 7,4′-tetrahydroxy-8-methoxyflavone (Ⅳ), 3, 5, 7,4′-tetrahydroxyflavone (Ⅴ), 5,7-dihydroxy-8,4′-dimethoxy-3-O-glucoside (Ⅶ), 5,7,4′-trihydroxy-8-methoxyflavone-3-O-glucoside (Ⅷ). One phenol acid compound was identified as ethyl gallate ( Ⅵ ). Among them, compound Ⅶ is a new compound that has never been reported. Except compound Ⅴ , all the other compounds were isolated from this genus for the first time.

Key words: Cercidiphyllum japonicum, Flavonol, 5,7-dihydroxy-8,4′-dimethoxy-3-O-glucoside