The constituents of Betula ermanii CHAM. in Japan were identified as follws. Fresh leaves : 20(S), 24(R)-epoxydammmaran-3β, 11α, 25-triol (1), 3-O-β-D-glucopyranoside of 1 (2), 2'-acetate of 2 (3), 11, 2'-diacetate of 2 (4), dammar-24-en-3β-, 11α-20(S)-triol (5), 3-O-β-D-2-O-acetylglucopyranoside of 5 (6). Outer bark : betulin (7), betulin 3-caffeate (8), oleanolic acid (9). Inner bark : (+)-lyoniresinol 3α-O-α-L-rhamnopyranoside (10), (-)-lyoniresinol 3α-O-β-D-xylopyranoside (11), 9, 9'di-O-feruloyl-(-)-secoisolariciresinol (12), acerogenin E (13), 3, 4, 5-trimethoxyphenol β-D-apiofuranosyl(1→6)-β-D-glucopyranoside (14), 4-(4-hydroxyphenyl)-2-butanol 2-O-β-D-apiofuranosyl-(1→6)-β-D-glucopyranoside (15), (+)-catechine 7-O-β-D-xylopyranoside (16), lupeol (17), monogynol A (18). Root outer bark : lupeol caffeate (19), betulin 3-caffeate (8), oleanolic acid caffeate (20), dammarendiol II 3-caffeate (21). Compounds 2, 3, 4, 6, 19 and 21 are new.