Examinations were made on the constituents of Lycopodium cernuum L. and Lycopodium inundatum L. From the former, a new triterpenoid, 16-oxo-21-episerratriol, and flavonoid, cernoside, together with the known alkaloids, lycocernuine (IV), cernuine (V), and triterpenoids, α-onocerin diacetate (VII), serratenediol diacetate (IIIa), serratriol triacetate (IX), 21-episerratriol triacetate (VIII) were isolated. From the latter, new alkaloids, anhydrolycocernuine (XXII) and LI Base A together with known alkaloids, lycocernuine (IV), lycopodine (XXI), and triterpenoids, α-onocerin diacetate (VII), serratenediol diacetate (IIIa), and acetyl p-cumaric acid (XV) were isolated. The structures of 16-oxo-21-episerratriol triacetate and anhydrolycocernuine were determined as XIII and XXII, respectively.