A new alkaloid, incarvilline, was isolated from the aerial parts of Incarvillea sinensis. By analysis of the IR, mass, 1H and 13C 2D NMR spectra and X-ray crystallography, the structure was determined to be N-methyl-4,8-dimethyl-7-hydroxyl-cyclopenta(C)piperidine-(7β,4R,8R). © 1992.