Abstract: The metabolites of calusterone (17β-OH-7β, 17α-dimethyl-androst-4-ene-3-one) in man has been investigated by GC/MS. After oral administration, the parent compound and seven metabolites were detected in the conjugated fraction. The extraction and fractionation of these metabolites were achieved by using XAD-2 column. The sample was derivatized with MSTFA/TMSI before GC/MS analysis. The mass spectra of the metabolites are presented and the metabolic pathway was discussed.