Technical Abstract: Changing economic and social conditions are threatening plant diversity on rangelands in Mongolia and China. Teams of collaborating scientists from the U.S.A., Mongolia, and China collected seed of rangeland plant species in Mongolia and Inner Mongolia, China, to preserve plant biodiversity from these countries. The U.S.A. portion of the seed was incorporated into the U.S. National Plant Germplasm System where it is freely available to scientists around the world. Subsequent field evaluations in Mongolia identified the most promising collections for revegetation of abandoned croplands, restoration of deteriorated areas around villages, and rehabilitation of areas disturbed by mining. An ongoing project in Mongolia is increasing seed of the most promising collections. These studies will assist in the use of these species for livestock production, revegetation, conservation, and reduced-input turf in Mongolia, China, the western U.S.A., and other countries around the world.