Abstract: Scanning electron microscopic studies on the structure of 7 saline-alkali tolerant dicotyls,Suaeda corniculata,Cynanchum chinense,Lappula intermedia, Potentilla supina and Artemisia anethifolia show that their roots have well-developed aerenchyma, and have the structural characters of saline-alkali and drought-tolerant.The subsidiaries on their leaf Surface such as epidermal hair,cuticle and waxy decorative patterns also show the stressreslstant structures.

Key words: Dicotyls, Structural characters, Grassland, carbon carrying capacity, ecological compensation criterion, carbon footprint