Ziwuling is a bigger existing secondary forest in the Loess Plateau;also, it is one of the forest areas of conservating water through afforestation in the national plan. The area and comprehensive functions of the forest have been reducing because of over-increasing population，more aggravated production activity, political faults sometimes，and unstrict administrative measures. To this end，the arthors suggested that this region should be classified as one of the key protective regions on national level in order to take some beneficial measures of recovering forest，and to bring its role of conserving soil and water and improving ecological environment into full play.