A new dimeric psoralen-type furanocoumarin,notopterol-(18-O-20′)-notopol(1),was isolated from Notopterygium incisum for the first time and its structure was elucidated by spectroscopic methods. A new dimeric psoralen-type furanocoumarin, notopterol- (18-O-20 ’) - notopol (1), was isolated from Notopterygium incisum for the first time and its structure was elucidated by spectroscopic methods.