Two new diarylheptanoids, carpinontriols A (1) and B (2), were isolated from the stems of Carpinus cordata, along with the known diarylheptanoid, casuarinondiol (3), and five known compounds, (+)-catechin (4), methyl gallate (5), methyl gallate 3-O-beta-D-glucopyranoside (6), methyl gallate 4-O-beta-D-glucopyranoside (7), and methyl gallate 3-O-beta-D-(6'-O-galloyl)-glucopyranoside (8). The structures of 1 and 2 were elucidated by spectral methods. Among the isolated compounds, compounds 4-6 and 8 showed radical-scavenging activity in the DPPH assay.