Abstract:Some constituents were isolated from the fresh whole plant of Lobelia davidii Franch. collected from Yunnan Province, with silica gel chromatography, ion exchange and preparative TLC. The structures except lelobanonoline, were identified by techniques comparision of their MS, IR, 1NHMR and 13C-NMR with the literature data thereof. They are β-sitosterol, β-amyrin palmitate, β-amyrin, norlelobanidine, norlobelanine, lelobanonoline, lobelanidine and norlobelanidine. Lelobanonoline is a new alkaloid with the structure of l-[6-(2-hydroxy-2-phenple-thyl)-l-methyl-2-piperidinyl ] butan-2-one.