Continuing the separation of the nonphenolic fraction of the combined alkaloids of the leaves of Liriodendron tulipifera L. on a column of silica gel, two individual alkaloids were isolated from a benzene-methanol (99 : 1) eluate. Base (I) was identified as d-isoremerine by comparison of physicochemical properties and mixed melting point with an authentic sample. Base (II) was characterized by mass, UV, IR, NMR spectra and derivative preparation (acetylation, methylation of d-caaverine to obtain O-methyl ether identical with II), and identified as the dextrorotatory form of 1-nornuciferine (d-nornuciferine). Thus, d-isoremerine and d-nornuciferine have been isolated from L. tulipifera for the first time.