Before Qin and Han Dynasty the loess plateau was with dense forestand grass, dressed in picturesque scenery, and praised as "How beautiful place it is. There are large lake and clear water" in many ancient booksand inscriptions on tablet.But since the War Period of the Spring andAutumn (770476 B. C. ) the ecological enviroment of the area has beendamaged by human being frequently through war destroyment. denudationto build palace, firewood gathering and taking off forest to reclaime,etc. It is thought that the main trouble root is in extensive cultivationwith little harvest, farming with rotate wasteland, which result in loessto be naked. crisscross gullies, serious soil and water loss and poor economy. The controlling policy suggested includes "taking vegetation construction, halting soil and water loss,developing forestry and husbandryas the main tasks, in order to realizethe grain selfsuficient". It couldbe expected soon that the goal of green hill and clear water, dense forestand rich harvest and prosperous economy is achieved if the policy isupholded.