A new sesquiterpene, hedyunchene A (1), was isolated from the rhizomes of Hedychium yunnanense, together with two known compounds 6 beta-hydroxystigmasta-4,22-dien-3-one (2) and 6 beta-hydroxystigmast-4-en-3-one (3). Their structures were determined on the basis of NMR (1D and 2D) and mass spectroscopic analysis.