[Objective] Effects of the implementation of the "Grain for Green" policy, relative to history, on oasis vegetation composition, soil physical, chemical and microbial properties, and soil enzyme activities were analyzed.[Method] To that end, plots of lands different in "Grain for Green" history (1, 2, 4, 8, 13, 20, 30 and 40 a) and a plot of farmland as CK in the Minqin Oasis were cited for exploration of effects of the practice on vegetation restoration and soil properties, using the spatial-temporal substitution method.[Result] Results show that in the 9 plots (including CK), representing natural succession of vegetation during a period of 40 years, a total of 43 species of plants were observed, and the vegetation evolved gradually from a community of annual herbaceous plants to that of shrubs only, showing strong continuity and progressiveness. With the increase in age, soil moisture content declined first, then rose and declined again, appearing like an inverted "N" in variation trend, and was higher in the upper soil layer than in the lower layer in the plots over 20 years in age; soil bulk density decreased gradually on the whole; soil particle size composition did not show any regular trend in variation, and was dominated with fine sands rather than clay; soil total nitrogen, soil available potassium, soil organic matter and soil microbial biomass carbon all rose first and then declined in content, while soil available phosphorus did not change much in content, but did in margin; soil bacteria and actinomycetes decreased to a different degree in population; with bacteria being in dominancy and reaching up to 611.46×10⁵Cfu.g^-1; and soil enzyme activities fluctuated, but on a generally declining trend. Moreover, with increasing soil depth, soil bulk density, soil nutrient contents and soil microorganisms generally decreased, and the phenomena of surface accumulation was quite obvious.[Conclusion] The cluster pedigree chart of the plots demonstrates that the 4^th years after the "Grain for Green" practice was implemented are critical for the land to have vegetation recovered in the Minqin Oasis. All the findings in the experiment may serve as a practical and theoretical basis for conservation and restoration of ecosystems in arid oases.