Abstract: Twenty compounds were isolated and purified from the fresh roots of Huaizhong NO.1 Rehmannia glutinosa by various chromatographic techniques such as Toyopreal HW-40C, Sephadex LH-20, silica gel and semi-preparative HPLC. Their structures were identified by analysis of physicochemical properties and spectral data, and determined as 3-methyl-2-(hydroxymethyl)-4H-pyrone-4-one (1), 3-amino-2-pyridine ethanol (2), (5'S)-2-oxo-N-phenylpyrrolidine-3-carboxamide (3), L-pyroglutamic acid methyl ester (4), indazole (5), uridine (6), adenosine (7), rehmanalkaloid C (8), 1-(3-ethylphenyl)-1,2-ethanediol (9), (3-ethylphenyl)-1,2-ethanediol (10), 2-hydroxymethylphenyl-1-O-β-D-glucopyranoside (11), mussaenoside (12), 11-methylforsythide (13), 7-deoxygardoside (14), 1-O-α-L-rhamnopyranosyl(1→6)-β-D-glucopyranoside (15), 6-deoxy-D-mannono-1,4-lactone (16), monoethylfumarate (17), daphneresinol (18), dihydroquercetin (19), rhamnopyranosyl vaniloyl (20). Compound 1 is a new compound, named as 3-methyl-2-(hydroxymethyl)-4H-pyrone-4-one, compounds 2 and 3 are new natural products, and compounds 4, 5, 9-11, 13, 14 and 16-19 are isolated from Rehmannia for the first time.