The characteristic of ecosystem changes along the environmental gradients and the soil is one of its important indicators. We studied the spatial variation and distribution of soil nutrient contents in Yilong lake area, located in the Longitudinal Range-Gorge Region with rich biodiversity and being one of the largest Platue Lakes of YunNan Province, China. Soil samples were taken from four areas along the different environmental gradients, concluding Northern Farm (NF), Northern Hill (NH), Southern Farm (SF) and Southern Hill (SH). The organic matter, total N, P, and K(TN,TP,TK), and available N, P, and K(AN,AP,AK) in the soil samples were measured. The soil quality index was calculated by principle component analysis, using the measured soil nutrient contents. Correlation matrix was created among various soil nutrient contents and altitude or soil moisture content for NH or NF, respectively. Average contents of soil nutrients were calculated in the studied four areas.Principle component analysis showed that the critical factor affecting the space distribution of the NH soil nutrients was not the altitude but the slope. The contents of most nutrients were lowest at the foot and the peak of the NH and were highest at the middle of it except the potassium. The soil of NH was rich in organic matter and total nitrogen. In NF, however, the soil nutrient contents gradually decreased with the decrease of soil moisture except the organic matter and total nitrogen, probably because some of organic matter and total nitrogen was moved by precipitation from the hill soil with high content of them to the farm near the road. The soil moisture played an important role to determine the soil nutrient contents distribution. The soil of NF was rich in potassium and phosphorus while the NH soils contained high contents of the organic matter and nitrogen. The soil of Yilong lake shore generally contained low content of phosphors but high content of potassium. The soil quality of the four studied areas was in the order: SF>NF>NH>SH, indicated by the integrated soil quality index.This study also investigated the relationship between the single soil nutrient factors and soil quality index and the environmental factors. The environmental factors included air humidity, soil moisture, slope, altitude, air temperature, slope shape, and orientation. The results showed that the air temperature, air humidity, orientation, and the slope shape played an important role to the phosphorus spatial distribution. On the other hand, the soil moisture, slope, and the altitude played an important role to the spatial distribution of the organic matter, total nitrogen and Potassium. In addition, the soil moisture was the critical factor affecting the soil quality. The regression equation between soil nutrient primary components and soil quality was: soil quality=1.842+0.465 N-PC1+0.214 N-PC-2 (N-PC was the primary component of the soil nutrient factors).