The exploration of the mutual relationships between soil microorganisms and different types of forages in desert steppes is crucial for maintaining and restoring desert steppe ecosystems. In this study， perennial forages [Stipa breviflora Griseb， S. glareosa P. Smirn， S. krylovii， Cleistogenes songorica （Roshev） Ohwi] and annual forage [Neopallasia pectinata （Pall） Poljak] in desert steppes were taken as the research objects to analyze the enhancement effects of soil microbial concentration on different species of forages. The results showed that： （1） Soil microbial concentration exerted a neutral effect on the growth of perennial forags， mainly due to the mutual offset between the negative effects of bacteria Sphingomonas and fungi Dominikia and the positive effects of bacteria norank_f_Longimicrobiaceae and fungi Rhizophlyctis on their growth. （2） Soil microbial concentration exerted an inhibitory effect on the growth of annual forage Neopallasia pectinata， and this effect intensified with the increase in microbial quantity. Soil microbial α diversity， Gemmatimonadaceae， Coprinopsis， Fusarium in rhizospheric soil， and Rubrobacter， Peziza in non-rhizospheric soil all showed inhibitory effects on its growth （P<0.05）. The analysis of key microbial groups provides a theoretical basis for subsequent related microbial studies， so as to enhance the growth stability of forages in desert steppes.

Soil microorganism  /  Desert steppe  /  Annual forage  /  Perennial forage  /  Enhancement effect