Two new triterpenoid hydrocarbons were isolated from the rhizomes of Davallia mariesii MOORE, together with neohop-13(18)-ene, hop-21-ene, hop-17(21)-ene, hydroxyhopane, cyclolaudenol and cyclobalanol. On the other hand, fern-9(11)-ene, ferna-7, 9(11)-diene, fern-7-ene, hop-22(29)-ene, hydroxyhopane and dryocrassol were isolated from the leaves of the same fern. The structures of two new compounds, hop-16-ene (1) and isohop-22(29)-ene (2), were elucidated on the basis of spectral data and chemical correlations with known compound.