A new alkaloid, stemoninine, obtained from the root of Stemona sessilifolia, and its stereochemistry have been elucidated by the analysis of the high resolution 1H-nmr spectrum; 1H, 1H-COSY; 13C, 1H-COSY shift correlated two-dimensional nmr spectra and 1H longrange shift; and 13C, 1H-COLOC- and nOe-correlated 2D-nmr techniques.Previously we isolated the new alkaloid stemoninine from the root of Stemona sessilifolia (Mig.) Frack et Sav. (Stemonaceae; formerly Roxburghiaceae) and elucidated its structure by ir, uv, 1H-nmr, 13C-nmr, and ms data (1,2). In the present paper, we further attempt to elucidate the structure and relative configuration of the molecule using 2D-nmr techniques such as 1H (1H, 1H-COSY), 13C-1H (13C, 1H-COSY) shift correlations and 1H-1H long-range couplings shift, 13C-1H long-range couplings shift (13C, 1H-COLOC) as well as nOe-correlated 2D-nmr techniques (NOESY). From the analysis of these spectral data of stemoninine, the structure 3 is proposed.