In addition to twenty-nine known compounds, two new guaiane sesquiterpenes and two new furanocoumarins were isolated from the chloroform extract of the rhizomes of Notopterygium incisum. The new structures were elucidated by means of spectroscopic methods including 2 D NMR techniques and mass spectrometry to be 8 beta-acetoxy-4 alpha,6 alpha-dihydroxy-1 alpha,5 alpha( H)-guai-9-ene (incisumdiol A, 1), 4 alpha,6 alpha-dihydroxy-1 alpha,5 alpha( H)-guai-9-ene (incisumdiol B, 2), 5-[(2 E,5 Z)-7-hydroxy-3,7-dimethyl-2,5-octadienoxy]psoralene ( 3) and 5-[(2,5)-epoxy-3-hydroxy-3,7-dimethyl-6-octenoxy]psoralene ( 4).