Abstract: Pinoresinol diglucoside was separated by silica gel column chromatography using chloroform-methanol-water (65:35:16) as the mobile phase, and then used as standard for its determination in the crude drug-Eucommia ulmoides Oliv by HPLC. Silica gel (5μm) was used as the stationary phase and chloroformmethanol-hexane-acetic acid (45:23:30:2) as the mobile phase. Detection was performed by UV at 280nm.The bark (phloem) of various samples contains 0～0.55% of pinoresinol diglucoside. Other parts of the bark do not contain the diglucoside.