Abstrcat Using the Caragana korshiskii. shrubbery of 17 years in Shanghuang as the studied object, this article analyzed the effect of different topography, site preparation modes and annual accumulated rainfall to the formation of morphological structure of the Caragana korshiskii. shrubbery. The height, the root depth, the number of branches and the biomass of Caragana korshiskii. shrubbery in different topography and preparation modes were studied. By using the principal component analysis, the results suggested: (1) The effect of different topography was significant to the tree height, root depth and biomass, but the number of branches was not. The effect of different site preparation was also significant to all biologic indices. (2) The effect of annual accumulated rainfall on the formation of morphological structure of Caragana korshiskii. shrubbery was high. By analyzing the regression about tree height, root depth, number of branches and biomass of Caragana korshiskii. with total precipitation, the curve of tree height , the number of branches and biomass were showed as "S" pattern, which suggested the correlation between the annual accumulated rainfall and the indices were very large.The relationship between root depth and the annual accumulated rainfall was the shape of exponential curve. (3) All growth indices have close relation. Tree height, branches and biomass were aboveground combined indices to the descriptive of plant and the root depth was the under-ground one