Abstract: Normal phase silica gel column chromatography, HP-20 macroporous resin column chromatography, Sephadex LH-20 dextran gel column chromatography, and semi-preparative liquid chromatography were used for the isolation and purification of the ethyl acetate parts of Thesium chinense to obtain 19 compounds, which were identified by NMR, MS and other spectroscopic techniques as isolariciresinol (1), matairesinol (2), (7R, 8R)-4, 7, 9, 9'-tetrahydroxy-3-3'-dimethoxy-8-O-4'-neolignan (3), calquiquelignan D (4), tricin4'-O-(erythro-β-guaiacylglyceryl)ether (5), luteolin (6), loliolide (7), (+)-epiloliolide (8), abscisic acid (9), nipagin methyl ester (10), ferulic acid (11), trans-p-hydroxycinnamic acid ethyl ester (12), p-hydroxy-benzoic acid ethylester (13), 5-O-feruloylquinic acid (14), 4-O-feruloylquinicacid-quinic acid-methylester (15), conoidol A (16), isozinopyridine (17), catechol (18), and pinnatifidanin A (19). Among them, compounds 1−6 and 8−19 were isolated from the plant for the first time. The isolated compounds 1, 5−12and 17 were tested for their bacteriostatic activity, in which compound 6 was more effective in inhibiting Bacillus subtilis.