Caragana microphglla is a stable shrub species for afforestation in thesemiarid loess hilly region. Its root system belongs to the tillering ca-tegory of taproot type and is relatively developed. The biennial-tetren-nial plant root system ranges from 1.5 to 4.0m deep and from 1.0 to 3.0wide. Most of the roots are distributed in the depth of less than 50cmsoil layer

and the distribution form changes gradually from column tocone-shaped as time goes on. The root system of C. microphylla has quite good plasticity and dif-fers evidently in growth under different locality that depends mainly onsoil structure

fertility and moisture. The way and quality of soil pre-paration exerts great influence on the growth of root system. There is certain correlation in growth between root system and thepart on ground of the plant. The length of biennial-tetrennial plant rootis about 5-6 times of plant height. The weight ratio of C. microphyllaroots to the part on the ground decreases with the increases of its age.