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 compre-hensively 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 vari-ables 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 phospho-rus 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 fluctuat-ed .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 .%以12个直接变量和3个间接变量为土壤质量评价指标体系，采用土壤质量指数法，对宁夏红寺堡扬黄灌区绿洲农田土壤质量早期动态变化进行了综合评价与分析。研究表明：在0～9年间，不同土壤变量的变化趋势不尽相同，其中土壤总有机碳从1．42 g·kg－1增长到4．48 g·kg－1，活性有机碳从0．31 g·kg－1增长到1．00 g·kg－1，阳离子交换量从4．30 cmol·kg－1增长到7．65 cmol·kg－1，钙磷比从4．13增长到12．46，粉粒含量从10．32％增长到20．50％，粘粒含量从15．09％增长到34．73％，都呈显著的单调线性增长趋势；而可溶性总盐从1．20 g · kg－1降低到0．49 g·kg－1、砂粒从74．60％降低到44．77％，呈显著的单调下降趋势；其他变量则表现出波动变化或相对稳定的格局。主成分分析把12个土壤变量归为土壤肥力和土壤离子环境两个主成分，在此基础上构建的土壤质量指数0～9年间的变化呈现出典型的S型增长曲线格局，其中钙磷比、CEC、总有机碳的动态与土壤质量指数变化最为相似。
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