[Objective] To explore the changes of soil physical and chemical properties and enzyme activities of four vegetation types in desert saline-alkali lands in the Hexi Corridor and their influencing factors，and to provide a theoretical basis for soil nutrient cycling and regulation mechanism in desert saline-alkali lands. [Methods] Taking the desert saline-alkali soil in the Hexi Corridor as the research object，four typical vegetation types，including Lycium ruthenicum Murr. single community（HH），L. ruthenicum and Phragmites australis community（HL）， L. ruthenicum and Alhagi camelorum Fisch. community（HT），L. ruthenicum and Tamarix chinensis Lour. community（HC），were selected. Three replicate plots were set up for each vegetation type. Through the combination of field investigation and indoor analysis，soil physical and chemical properties（including organic carbon，total nitrogen，total phosphorus）and enzyme activities（including urease，alkaline phosphatase，nitrate reductase，nitrite reductase）of the four vegetation types were measured. Variance analysis and redundancy analysis were used to evaluate the differences in soil physical and chemical properties and enzyme activities，and the influencing factors were analyzed. [Results] In the soil of the four different vegetation types in the Hexi Corridor，organic carbon content increased with the increase of soil depth，being the highest in HC and the lowest in HH，and the difference was significant（p<0.05）. Total nitrogen content decreased with the increase of soil depth，being the highest in HH and the lowest in HC，and the difference was significant（p<0.05）. There was no significant change in total phosphorus（p>0.05）. The activities of urease，alkaline phosphatase，nitrate reductase and nitrite reductase decreased with the increase of soil depth，showing the phenomenon of surface aggregation. The activities of alkaline phosphatase，nitrate reductase and nitrite reductase were significantly different among different vegetation types（p<0.05），being the highest in HL，HH and HT，and the lowest in HT，HC and HH， respectively. Total nitrogen content was significantly positively correlated with urease and nitrate reductase activities（p<0.05）. In the 20—40 cm soil layer，organic carbon content was significantly negatively correlated with urease and nitrate reductase activities（p<0.05）. [Conclusion] The changes of different vegetation types and soil layers cause significant changes in soil physical and chemical properties，and then regulate the changes and distribution of soil enzyme activities. Soil total nitrogen and organic carbon contents are the key factors affecting soil enzyme activities，and can better explain the distribution and change characteristics of soil enzyme activities.