Planting contour hedgerows is a good management measure for the continuing development of agriculture in a mountainous area, it's a efficient measure to prevent and cure the water and soil erosion and degeneration of soil in the sloping field. There are restrain and promotion between hedgerows and crop, especially the competition of the nutrient, light, water and air when the promotion of hedgerows. Those facts limited the diffusion of hedgerows. Vetiveria Zizanioides (abbreviated as VZ) and Amorpha fruticosa (abbreviated as AF) were selected as hedgerows, and wheat and soybean were taken as tested materials in the pot trials. There were four treatments included, which were single crop (wheat or soybean), non-isolation between two plants, net isolation and clapboard isolation.15N isotopic tracer technique was also used in the experiment to mensurate the content of nutrient and the quality absorbed by the hedgerows and crop. Results indicated: 1) both VZ and AF had significant influence on N uptake by wheat, however, AF inhibited N uptake soybean and VZ improved N nutrition; 2) AF inhabited the uptake of phosphorus by wheat but enhanced that by soybean, whereas VZ strengthened the P uptake by both wheat and soybean; 3) two hedgerows could improve potassium uptake by both crops; 4) competition of AF to N and uptake to P or K were stronger than those of VZ, but uptake of N followed an opposite sequence; 5)the effect of two species of hedgerows on wheat was weaker than that of inter wheat, but was stronger than that of inter soybean individuals. The conclusion have been indicated the promotion and competition of the nutrient between VZ, AF, wheat and soybean. It provided theoretics references for the widely diffusion of planting contour hedgerows in the mountain region.