In order to study the chemical constituents in the water extract of the stem of Nauclea officinalis, column chromatography over D101 macroporous resin and silica gel and an automatic purification system were used to isolate and purify the chemical constituents from the extract. Nine compounds were obtained. By analysis of the physicochemical properties and spectral data, their structures were identified as naucleamide G (1), 3, 4-dimethoxyphenol-beta-D-apiofuranosyl (1-->6)-beta-D-glucopyranoside (2), kelampayoside A (3), 3alpha, 5alpha-tetrahydrodeoxycordifoline lactam (4), naucleamide A-10-O-beta-D-glucopyranoside (5), pumiloside (6), 3-epi-pumiloside (7), strictosamide (8) and vincosamide (9), separately. Among them, compound 1 is a new compound, compound 2 was found in plants of the genus Nauclea for the first time, and compounds 3 and 4 were isolated from this plant for the first time.