The seeds of Zizyphus jujuba Mill. var. spinosa (Bunge) H. H. Hu ex H. F. Chow ( 酸 枣仁 ; family Rhamnaceae) has been used as traditional medicine to treat sedation and hypnosis in Eastern Asia. Our previous studies have indicated that the ethanolic extract of Z. jujuba var. spinosa (DHP1401) improves memory impairment, a common symptom of various neurological diseases. In this study, the chemical composition of DHP1401 has been isolated and characterized. Additionally, we investigated the anti-dementia effects of major components of DHP1401 on memory impairment by scopolamine, a muscarinic receptor antagonist. Phytochemical constituents were isolated from the dichloromethane, ethylacetate, n-butanol fractions of DHP1401 using repeated chromatography and prep-HPLC systems to yield 13 compounds. The isolated compounds were elucidated as pinostrobin (1), 6-demethoxyafromosin (2), diosmetin (3), buddlenol C (4), ficusequilignan A (5), ceanothic acid (6), alphitolic acid (7), naringenin (8), 6'''-feruloylspinosin (9), nicotiflorin (10), swertisin (11), spinosin (12), magnoflorine (13) by spectroscopic analysis. Among them, swertisin (11) and spinosin (12), which are well known as the major components of Z. jujuba var. spinosa, attenuated the scopolamine-induced cognitive deficit in passive avoidance task. Further studies will focus on the profiling of components in DHP1401 and the characterization of the constituents responsible for the anti-dementia effects.