Abstract: Bioactive humic substances(BHS) were applied to restore the desertified soil in Xinjiang Glycyrrhiza uralensis production area.The dynamic change of soil total nitrogen and organic carbon contents during the 90th and 190th day after application of BHS was studied,followed by analysis on the change of other soil nutrients contents.Comprehensive evaluation of the restoration effects!of BHS was analyzed by principal component and cluster analysis method.The results showed that BHS could improve significantly soil main nutrients contents within 190 days and the optimal application rate was 450kg·ha-1.The content of soil total nitrogen,organic carbon,available nitrogen,available phosphorus,available potassium,extractable humic substance carbon,fulvic acid carbon and humic acid carbon improved by 21.6%,15.9%,36.6%,20.0%,13.9%,21.0%,17.4% and 25.2% respectively comparing with CK.The restoration effect with different application rates of BHS,according to principal component method,ranked as follows: 450kg·ha-1> 750kg·ha-1> 600kg·ha-1>300kg·ha-1>150kg·ha-1>CK.

Key words: Bioactive humic substances, Bioactive humic substances, Xinjiang, Glycyrrhiza uralensis production area, Degraded and desertified soil, Restoration, Evaluation