To study the lignans compound from Eucommia ulmoides barks and evaluate their protective effects on high-glucose-stimulated human renal mesangial cells.The barks of E. ulmoides was crushed and extracted with purified water.HPD-100 macroporous resin,Silica gel,Sephadex LH-20 and Semi-preparative HPLC were used to separate compounds in the aqueous extract,and their structures were identified based on physicochemical properties and spectral analysis.Six lignans were isolated and identified as caruilignan D (1),(-)-epipinoresinol (2),(+)-pinoresinol 4-O-β-D-glucopyranoside (3),(-)-pinoresinol 4-O-β-D-glucopyranoside (4),(+)-medioresinol 4-O-β-D-glucopyranoside (5) and (+)-medioresinol 4′-O-β-D-glucopyranoside (6).Compound 1 was isolated from E. ulmoides for the first time.The effect of isolated lignans on cell viability in high-glucose-stimulated human renal mesangial cells (HRMCs) with abnormal proliferation was evaluated by MTT assay.It was found that compound 5 can inhibit cell proliferation in a dose dependent manner,indicating that compound 5 exerts protective activity on high-glucose-stimulated HRMCs.