【Objective】 This study investigated the effects of water and nitrogen treatment on soil meso- and micro-fauna communities in desert steppe to understand the ecological responses of desert steppe to global change.【Method】 During growing season in 2014,the effects of control (CK,natural rainfall),rainfall removal (R),water addition (W),N addition (N),rainfall removal and nitrogen (R+N),and water addition and nitrogen (WN) on meso- and micro-fauna communities in soil of the Stipa breviflora desert steppe of Siziwang Banner,Inner Mongolia were studied.【Result】 In Stipa breviflora desert steppe,a total of 333 079.5 ind/m~2 were captured,and they were classified into 4 phyla,10 orders and 47 families.Collembola,Arachnida and Insecta were the major groups.The communities were dominated by Neanoridae and Isotomidae.The communities mainly consisted of dominant and common groups.Water addition and water addition combined with N addition stimulated the density of soil meso-fauna in desert steppe while rainfall removal and rainfall removal combined with N addition reduced individual density of soil fauna.The interaction between water and nitrogen had positive effect on soil fauna individual density,except for group richness.Soil meso- and micro-fauna communities in Stipa breviflora desert steppe had surface clustering feature,and individual number at 0-10 cm in all treatments was significantly higher than in 10-20 cm (P<0.05).【Conclusion】 The density of meso- and micro-fauna is more sensitive than group richness with increasing precipitation and N deposition in future.