<jats:title>Abstract</jats:title><jats:p>A new <jats:italic>Lycopodium</jats:italic> alkaloid together with a phenolic glycoside—arbutin, were isolated from the whole plant of <jats:italic>Huperzia serrata</jats:italic>. The new compound was assigned the trivial name of huperzine I. The structures of these two compounds were determined on the basis of spectral evidence.