Abstract:This study aimed to explore the relationship between different slope aspects and soil nutrient content,and to provide the theoretical basis for vegetation restoration and reconstruction at Lanzhou rain-fed ecological zones.The soil organic matter,available P,available K,available N,and their correlation were analyzed at different soil depth from the different slope aspects (South-facing slope,half sunny slope and North-facing slope) at the Tiger Terrace Rain-fed Ecological Experiment and Demonstration Zone,in Shuifu Township,Gaolan County,Lanzhou.The results showed that soil nutrient content decreased significantly with the increasing soil depth,and followed a trend of south-facing slope ＞ half sunny slope ＞ north-facing slope.The slope aspects had a significant and positive correlation with soil organic matter and available N content (P＜0.005).Soil depth showed a significant and negative correlation with soil organic matter,available P,available K and available N content (P＜0.005).There was a significant and positive correlation between soil organic matter,available P (P＜0.001),available K and available N (P＜0.005).Soil organic matter content and available N were significantly affected by soil depth,slope aspects (P＜0.001) and their interactions (P＜0.05).As soil nutrient content was generally low,we suggest that plants with strong resistance should be selected and planted at the suitable sites,with the appropriate application of organic fertilizers for soil rehabilitation.