| This research was implemented to acknowledge thoroughly the early dynamics, characteristics and driving processes of soil quality in Yanghuang irrigation oasis farmland of northwest China, searching for a proper way in comprehensively assessing the soil quality and providing a theoretical basis for the healthy and sustainable utilization of soil in the irrigated area. The soil quality index method was employed using soil quality evaluation index system including 12 direct variables and three indirect variables. Our research showed that within 0～9 years, the trends of different soil variables varied, including soil organic carbon (from 1.42 g·kg-1 to 4.48 g·kg-1), active organic carbon (from 0.31 g·kg-1 to 1.00 g·kg-1), cation exchange capacity (from 4.30 cmol·kg-1 to 7.65 cmol·kg-1), calcium and phosphorus ratio (from 4.13 to 12.46), silt (from 10.32% to 20.50%) and clay content (from 15.09% to 34.73%). All these variables displayed an increasing tendency. However, total soluble salt (from 1.20 g·kg-1 to 0.49 g·kg-1), sand (from 74.60% to 44.77%) tended to become declined sharply, while other variables were relatively stable or fluctuated. A Principal component analysis had classified 12 variables into two main groups as the soil fertility and the soil ion environment. Based on this, soil quality indexes changes showed a typical S-shaped curve pattern within 0～9 years, among which the dynamics of phosphorus ratio, CEC, total organic carbon and the changes of soil quality were mostly similar. |