A known compound, serratidine ( 1 ), along with three hydroxylated serratidine alkaloids, 6 f -hydroxyserratidine ( 2 ), 4 f -hydroxyserratidine ( 3 ) and 4 f ,6 f -dihydroxyserratidine ( 4 ) were isolated from the CHCl 3 fraction of basic materials of whole plant of the Chinese medicinal herb Huperzia serrata . The relative configurations of the above compounds were determined based on 2D NMR studies.