Two new alkaloids, lycojaponicumins D (1) and E (2), were isolated from the club moss Lycopodium japonicum. Their structures were elucidated by spectroscopic methods, calculated ECD, CD experiments and X-ray diffraction analysis. Lycojaponicumin D (1) possesses an unprecedented 5/7/6/6 tetracyclic skeleton formed by an unusual C3-C13 linkage, which is first reported in Lycopodium alkaloids. The plausible biogenetic pathway of 1 is proposed.