Abstract: Wu wei zi; Schisandra chinensis, is a commonly used Chinese traditional drug. Its allied species have also been widely used in folk medicine in China. Wu wei zi has been recently reported to be capable of lowering serum glutamic-pyruric transaminase (SGPT) level in patient with hepatitis.Twenty samples of the seeds and stems belonging to Schisandra species were analysed for their lignan derivatives: Wuweizisu A, wuweizisu B, wuweizisu C, wuweichun B, wuweizi ester A, wuweizi ester B, schisantherin C, schisantherin D and schisantherin E. The results indicatethat there are ubiquitous existance of these components except the stem of Schisandra micrantha which contains only a trace amount.The content of the total lignans of seeds varies according to species and localities of collection between 7.17～19.2%, e g Schisandra chinensis 18.1～19.2%, S. rubriflora 16.4% and S. lancifolia 13.2%; and Stems 1.28～10.25%, among them S. sphenanthera and S. chinensis were the highest (cf Tab 2).Species of Schisandra were tested for their SGPT-lowering property, while all of them exhibited some effect, S. chinensis, S. rubruflora, S. lancifolia and S. sphenanthera etc showed distinct activity, which may serve as new sources for SGPT lowering drugs (cf Tab 2)Several active components in three samples of two Schisandra species were determined (cf Tab 3) and the total lignan content of S. chinensis collected in different seasons were also estimated. The results indicate that the contents are higher between May and July.