A new chemotype of Microlepia marginata, P-type strain, was found in the Central districts of Japan. The two main constituents were characterized to be 2 beta,15(R),16-trihydroxy-ent-pimar-7-en-3-one (fumotoshidin A) and 3 alpha-alpha-L-arabinofuranosyloxy-15(R),16-dihydroxy-ent-pimar+ ++-7-ene (fumotoshidin arabinoside). The young fronds of this strain have reddish stripes, which is a common feature to Y-type strains also containing ent-pimarane-type glycosides.