Through three years experiment about improvement of discarded salkaline land by biomeasures in Chaidamu Basin from 1998 to 2000, the results showed the effect was very notalbe. Total salt content decreased with plant growth. In 0~30cm soil layer the total salt content decreased from 1.518% to 0.126%, mean desalinization rate was 91.7%. The salt did not gather in top layer of soil notably. The seasonal change of total salt content was keep in U carve. Primary productivity increased highly by rehabilitation. ...