In order to study phytoremediation of Tamarix ramosissima on saline-alkali soil and its effective range.Total salt and ionic contents of saline-alkali soils and characteristics of nutrient partition were analyzed based on field comparative test with saline-uncultivated land as CK.The results show that Tamarix increased nutrient contents of the saline-alkali soils,but decreased pH,total salt and ionic contents.Compared with CK,soil organic matter(SOM),available N,and available P at surface(0—20 cm) increased 30.5%,49.8% and 51.4%,respectively,and at sub-layer(20—50 cm) increased 78.8%,21.3% and 25.0%,respectively.The pH value was 0.3 units lower than CK at surface layer(0—20 cm),but was 0.4 units higher at sub-layers(20—50 cm).The desalination rate at surface layer and sub-layer were 86.4% and 88.2%,respectively,while ESP decreased 75.4% and 53.8%,respectively.Meanwhile,Tamarix exhibited selective absorption for Na+ and Cl-,with a significant higher reduction amplitude than other ions,such as Ca2+,Mg2+,K+ and SO2-4.An optimizing region with "lower total salt,lower pH and higher SOM" was formed in a layer of 0—25 cm depth within 15 cm to Tamarix.An reasonable Tamarix arrangement that could fully realize its biological and non-biological functions will be the key to improve physical and chemical properties of saline-alkali soils for sustainable development.