Abstract: 16 compounds were isolated and purified from methanol extract of the seed of Arctium lappa L. Among them,15 chemical constituents were identified by physico-chemical and spectroscopic analysis as actiin (1),arctigenin (2),matairesinol (3),lappaol B (4),isolappaol A (5),lappaol A (6),(+)-Diasyringaresinol (7),tanegool (8),arctignan F (9),lappaol F (10),lappaol C (11),arctignan D (12),arctignan E (13),lappaol H (14).Compound 7 and 8 were firstly isolated from the burdock seed.

Key words: Arctium lappa L., Compositae, lignans, chemical constituents