To study the chemical constituents of Eucommia ulmoides in Guizhou Province.Silica gel, Sephadex LH-20, RP-18, MCI and semi-preparative HPLC were used to study the chemical constituents of Eucommia ulmoides, and the chemical structures were elucidated by application of spectral data.16 compounds were isolated from the bark of Eucommia ulmoides. Their structures were identified as β-sitosterol (1), cycloeucalenol (2), betulinic acid (3), 24-methylenecycloartenone (4), cycloeucalenone (5), salicifoliol (6), pinoresinol (7), genipin (8) , alternariol (9), balanophonin (10), eucommidiol (11), pinoresinol-4'-O-β-D-glucopyranoside (12), eucommiol (13), deoxyeucommiol (14), 8-hydroxypinoresinol (15), and dehydrodiconiferyl alcohol -γ'-O-β-D-glucopyranoside (16).Seven compounds, including compounds 2,4 - 6,9, 10 and 15 are isolated from Eucommia ulmoides for the first time, and compound 14 is isolated from the bark of Eucommia ulmoides for the first time.