From the 95% EtOH extract of the cortexes of Polygala tenuifolia, four new phenones and three known xanthones were isolated. The structures of the four new phenones were identified as 4-O-[alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl]-2-hydroxyl-6-methoxybenzophenone (tenuiphenone A, 1), 3,5-di-C-beta-glucopyranosyl-2,4,6,3'-tetrahydroxybenzophenone (tenuiphenone B, 2), 2',4',6'-trihydroxyphenyl-(24Z)-triacontene-1-one (tenuiphenone C, 3), 2',4',6'-trihydroxyphenyl-(26Z)-dotriacontene-1-one (tenuiphenone D, 4) respectively, on the basis of spectroscopic analyses. The isolation of 1 and 2 supplied an evidence for the hypothesis that xanthone was biosynthesized from benzophenone in the plants.