Abstract: Ziwuling(107°30′～109°40′E,33°50′～36°50′N) is situated in the center part of Loess Plateau.the transitional zone between semi-humid and semi-dry climate,and its flora belongs to Loess Plateau subregion,North China region,Sino-Japan forest subkingdom,Holarctic kingdom.There are 689 species of seed plants belonging to 361 genera and 94 families,among which,big families and big genera play important roles.The Ziwuling's flora could be divided into 15 distribution types and 12 subtypes,among which,the North temperate,old world temperate,pantropic,and e-Asia are important types.The analysis of the Ziwuling's basic floristic characteristics of seed plants showed that the flora was comparatively rich in species,geographical elements were diversiform,transitional characters of geography were obvious,and temperate components were dominant.The northern flora was different from the southern one,but there was no evident distinction in the dangling flora.

Key words: Western Erdos, Soil, Tetraena mongolica, Micro-elements contents