The investigation of soil quality indices as affected by groundwater irrigation is of great significance to prevent and control soil degradation mainly in semi-arid steppe. Research has recently shown that irrigation can significantly improve biomass production of grasslands, but has yet to address the impact of irrigation on its soil quality. Here we determined to explore the effects of groundwater irrigation on soil quality of typical steppe dominated by Leymus chinensis and Stipa krylovii vegetation in the Xilin Gol grassland of China. Analysis of 11 different soil parameters at depths of 0-20 cm, 20-40 cm and 40-60 cm after a year of irrigation showed that irrigation did not pose soil salinity and sodicity risk. Average values for sodium adsorption ratio (SAR), pH and electrical conductivity (EC) all fell below standard limits. Compared with the control samples, soil organic matter (SOM) increased while available nitrogen (AN), available potassium (AK) and available phosphorus (AP) tended to decrease, although not significantly. Principal component analysis found that EC, SOM and pH form a minimum data set (MDS) for assessing soil quality of irrigated land. Irrigation led to slightly higher SQI values for Leymus chinensis grassland but did not significantly change SQI values for Stipa krylovii grassland. The results of this study can inform sustainable management of grasslands in semi-arid areas and other studies of steppe ecosystems.