A new species of Orchidaceae， Oreorchis bashanensis Wang Yong from Dabashan mountain area in Shaanxi was reported. The species was closely related to O.patens. Comparing with O.patens， the new species was decedious. The leaves fell during its flowering period. During its nutritional growth period， there were 2-3 leaves on each individual. It had larger pseudobulb and leaf blade. The lateral petals were erect. The claw of lip petal was about half the length of the whole lip petal. The orange callus protruded between lateral lobes on lip. However， O.patens was evergreen， and it had 1-2 leaves on each individual. The claw of lip petal was about 1/4 the length of the whole. The lateral petals were curved. The longitudinal lamellae was white or pale yellow. The type specimens were deposited in Herbarium of Shaanxi University of Technology（HZTC）.