A new lignan diglycoside was isolated from the bark of Eucommia ulmoides OLIV. (Eucommiaceae) and its structure was established as (+)-medioresinol di-O-β-D-glucopyranoside (1) by means of chemical and spectral studies. (+)-Pinoresinol di-O-β-D-glucopyranoside (2), liriodendrin (3) and (+)-pinoresinol O-β-D-glucopyranoside (4) were also isolated.