A known compound, serratidine (1), along with three hydroxylated serratidine alkaloids, 6alpha-hydroxyserratidine (2), 4alpha-hydroxyserratidine (3) and 4alpha,6alpha-dihydroxyserratidine (4) were isolated from the CHCl3 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.