Grass is the food of livestock, and is the material foundation of the development of stockbreeding. In order to select a kind of eminent grass which is adaptable to the northern China, the present thesis studies ten kinds of grasses from Gramineae, Bromus biebersteinii,Bromus inermis,Festuca arundinacea ,Festuca rubra,Dactylis glomerata ,Phleum pratense,Agropyron desertorum,Agropyron smithii,Elytrigia elongate and Phalaris arundinacea,and also explores the physiological aspects of their drought r...