Abstract: A simulated experiment was conducted to determine the role of wastewater dixcharged from an amino-acidfactory in improving the characteristics of purple dryland soil. The results, which were consisted with the field investigationand analysis, showed that nitrogen and organic matter contents in the soil had been considerably increased;soil moisturecondition had been improved and water loss rate from the soilhad been decreased after the input of the wastewater. However,the negative effects as the accumulation of Cl iron and salt,increasing activity of the Cu,Zn,Mn,Pb and other heavy tnet-als were also observed in the experiment. These results werefurther confirmed with field investigation and sample analysis.