Three lycopodium alkaloid N-oxides, huperzine | (1), huperzine K (2) and huperzine L (3) were obtained from Huperzia serrata (Thunb.) Trev. Their structures were elucidated by spectroscopic methods and the relative configurations of 1 and 3 were established via NOESY NMR observations; optical rotation values and CD data are presented.