Abstract: The metabolic transformation of schizandrin, isolated from the kernelof Schizandra chinensis Bill,was studied in vitro with phenobarbital- induced rat liver micro-somal fractio containing the NADPH-generating system. The major metabolites wereisolated by preparative HPLC and identified as 7,8- dihydroxy-schizandrin, 7, 8- dihy-droxy-2- demethyl schizandrin and 7, 8- dihydroxy- 3- demethyl schizandrin by UV,NMR, MS spectral analysis. The 7, 8 - dihydroxy- schizandrin was confirmed further bycomparison with spectral and chromatographic behavior of the authentic compound. Themetabolic biotransformation of schizandrin in vivo was also determined.