Abstract:For comprehensive understanding, effective managing and protecting the saline-alkali soil of Luyang Lake in Weinan City, Shannxi Province, the authors analyzed the physical properties and salinity characteristics in the region. The principal component analysis combined with norm values were employed to select the indexes and establish the minimum data set, in which, organic matter, alkali-hydrolysable N, available P, available K, ESP, CEC, conductivity, and soil bulk density were selected as indexes for evalulating soil quality. The results showed that the soil texture was relatively heavy with more clay. The values of membership functions of the indexes revealed that organic matter(0.31), alkali-hydrolysable N(0.39), available P(0.26), and available K(0.38) were the major limited soil nutrients factors in the region. The membership degrees of soil bulk density, CEC and ESP were 1, 0.64 and 0.61, respectively, it indicated that the soil was compacted, but the alkaline was very extremely high. In short, the comprehensive index was 0.277 calculated by using the weighted index summation method to evalulate the soil fertility, which illustrated that the soil fertility in this region was at a low level. Therefore, it need to take appropriate improvement measures to improve soil fertility in Luyang Lake region.